US20070001514A1 - Method and System for Voltage Tracking and Sequencing in a Power Supply - Google Patents
Method and System for Voltage Tracking and Sequencing in a Power Supply Download PDFInfo
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- US20070001514A1 US20070001514A1 US11/531,165 US53116506A US2007001514A1 US 20070001514 A1 US20070001514 A1 US 20070001514A1 US 53116506 A US53116506 A US 53116506A US 2007001514 A1 US2007001514 A1 US 2007001514A1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/102—Parallel operation of dc sources being switching converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/36—Means for starting or stopping converters
Definitions
- This invention relates generally to power supplies and more particularly to a method and system for voltage tracking and sequencing in a power supply.
- Power supplies are required in most every electronic device used today.
- An example use of a power supply is in an Ethernet switch.
- Such power supplies often require multiple different power levels for various portions of the Ethernet switch.
- a given power level is sometimes referred to as a power rail.
- Such power supplies often receive one voltage level as an input, such as 12 volts and generate numerous different power levels through a plurality of power converters.
- Series element control involves a voltage tracking controller, large series pass field effect transistors, and a set of multiple power supplies.
- the voltage tracking controller senses the output voltage and linearly controls the gate voltage to the series pass field effect transistors. This requires the series pass field effect transistors to be able to pass the entire load of the power rail with minimal voltage drop. This approach can be expensive, reduce reliability, generate heat, and consume board real estate.
- Shunt element control involves monitoring a voltage delta between two rails and linearly controlling the gate from a field effect transistor shorting the two rails.
- the field effect transistor must be capable of handling large currents associated with shorting high current rails. Power is dissipated only during start up and shut down, unlike the series element method.
- clamp diodes involves simply attaching a Schottky diode between power rails. If the higher voltage rail falls below the lower rail, the load of the lower rail is increased to bring the rails down together. This approach has a problem of possible overloading of the lower voltage supply, causing undue stress. It also requires diodes large enough to clamp the rails together. The diodes are physically large and costly.
- a power good signal may be used to enable a lower voltage rail.
- This solution is suitable for voltage sequencing, but not useful for voltage tracking. A large number of small logical elements is required.
- a resistor divider is used off of a higher voltage rail to generate a reference for the lower voltage rail pulse width modulator.
- a lower voltage reference ramps up or down to follow the upper rail. This feature does not accommodate voltage margining.
- a method for controlling multiple voltages in a power supply includes providing a plurality of DC to DC power converters.
- Each power converter includes a pulse width modulator controller having a control pin.
- the method also includes detecting when a voltage supply to the power controllers reaches a particular level. After the particular level is met, the method includes providing a respective rising ramp control signal to each respective control pin of the pulse width modulator controller such that each respective power converter generates desired voltage level over time characteristics.
- Some embodiments of the invention provide numerous technical advantages. Some embodiments may benefit from some, none, or all of these advantages. According to one embodiment, voltage tracking and sequencing may be achieved while still allowing voltage margining, which is desirable. In addition, according to one embodiment of the invention, voltage tracking and sequencing may be performed using relatively inexpensive devices and wasting virtually no power.
- FIG. 1 is a block diagram illustrating portions of a power supply according to the teachings of the invention
- FIG. 2 is a circuit diagram illustrating portions of each of the power converters of FIG. 1 ;
- FIG. 3 is a circuit diagram illustrating the voltage tracking and sequencing circuit of FIG. 1 ;
- FIG. 4A is a circuit diagram illustrating a voltage differential protection circuit of FIG. 1 ;
- FIG. 4B is a circuit diagram illustrating a second voltage protection circuit of FIG. 1 ;
- FIG. 4C is a circuit diagram illustrating a third voltage protection circuit of FIG. 1 ;
- FIG. 5 is a graph of voltage versus time illustrating the rise and fall of power rails of the power supply of FIG. 1 ;
- FIG. 6 is a flowchart illustrating a method for controlling voltage levels in a power converter.
- FIGS. 1 through 6 of the drawings like numerals being used for like and corresponding parts of the various drawings.
- FIG. 1 is a block diagram illustrating portions of a power supply 10 according to the teachings of the invention.
- Power supply 10 includes a plurality of power converters 12 , 14 , 16 , 18 , and 20 .
- five power converters are utilized and the characteristics of the power converters are as follows:
- Power converter 12 converts 12 volts DC to 1.8 volts DC.
- Power controller 14 converts 12 volts DC to 2.5 volts DC.
- Power controller 16 converts 12 volts DC to 3.3 volts DC.
- Power controller 18 converts 12 volts DC to 1.35 volts DC.
- Power controller 20 converts 12 volts DC to 1.5 volts DC.
- the teachings of the invention are applicable to any suitable number of converters as well as any levels of power conversion.
- Each power converter receives as input twelve volts at a respective node 11 and generates a voltage at its output node.
- Power converter 12 generates 1.8 volt on output nodes 22 .
- Power converter 14 generates 2.5 volts on output nodes 26 .
- Power converter 16 generates 3.3 volts across nodes 30 .
- Power converter 18 generates 1.35 volts on node 34 .
- Power converter 20 generates 1.5 volts on node 38 .
- the output node of each power converter is also referred to as a power rail.
- Voltage tracking and under voltage lockout circuit 52 includes a voltage tracking circuit 203 and an under-voltage lockout circuit 202 , as illustrated in FIG. 3 .
- voltage tracking circuit 203 receives a digital input from under voltage lockout circuit 202 and from voltage differential protection circuits 54 , 56 , and 58 .
- Under voltage lockout circuit 202 monitors a nominal 12 volt power supply at node 11 , and based upon the detected actual level outputs appropriate control signals over lines 60 , 62 , 64 , 66 , 68 to respective ones of the power converters, as described in greater detail below in conjunction with FIG. 3 . In general, however, under voltage lockout circuit 202 detects when the supplied voltage provided at node 11 reaches a predetermined level and in response initiates turning on of the power converters by providing appropriate voltage levels to each of the power converters 12 , 14 , 16 , 18 , and 20 . Conversely, under voltage lockout circuit 202 initiates turning off the power converters when it determines the supplied voltage is too low.
- Each of voltage differential protection circuits 54 , 56 , and 58 monitors voltage differentials between the rails of various pairs of power converters.
- voltage differential protection circuit 54 monitors nodes 30 and 34 associated with power converters 16 and 18 .
- Voltage differential protection circuit 56 monitors nodes 30 and 26 associated with power converters 16 and 14 .
- voltage differential protection circuit 58 monitors nodes 26 and 22 associated with power converters 14 and 12 .
- FIGS. 3A-3C The operation of each of these voltage differential protection circuits is described in greater detail in conjunction with FIGS. 3A-3C .
- a control signal is transmitted to each respective power controller over lines 70 , 72 , 74 , 76 , and 78 by protection circuit 54 indicating each power converter should shut down in an orderly fashion to maintain tracking requirements, thereby avoiding undesirable differential voltages, which could lead to damaged load integrated circuits.
- Control signals are transmitted over lines 80 , 82 , 84 , 86 , and 88 for protection circuit 56 .
- Control signals are transmitted over lines 90 , 92 , 94 , 96 , and 98 for protection circuit 58 .
- each ramp circuit is designed to have a particular time constant such that the respective power converter, through its soft start controls, either begins generating an output voltage or begins terminating an output voltage according to a particular respective voltage ramp that results in each of the power rails associated with each respective power controller ramping on or ramping off according to a desired voltage delta with respect to the other power rails.
- Appropriate design of the respective ramp circuits determines the respective output voltage versus time characteristics.
- the teachings of the invention recognize that utilization of a soft start input to a portion of the power converters enables one to control the voltage levels generated by power converters 12 , 14 , 16 , 18 , and 20 , and therefore provides control of the relative voltage versus time characteristics. Additional details are described with reference to FIGS. 2 through 6 .
- FIG. 2 is a circuit diagram of portions of power controller 12 , as an example. Power controllers 14 , 16 , 18 , and 20 are formed similarly to power controller 12 , with the differences described below.
- Power converter 12 includes a ramp circuit 101 , a pulse width modulation controller 100 , and additional circuitry 122 .
- ramp circuit 101 receives input at node 42 from voltage tracking circuit 203 , which is controlled by under voltage lockout circuit 202 , as well as voltage differential protection circuits 54 , 56 , and 58 and constant current input from soft start pin 106 .
- the corresponding ramp circuit receives input at node 44 ; for power controller 16 , the corresponding ramp circuit receives input at node 46 ; for power controller 18 , the corresponding ramp circuit receives input at node 48 ; and for power controller 20 , the corresponding ramp circuit receives input at node 50 .
- Ramp circuit 101 ramps, for a particular time constant determined predominantly by capacitor 104 , resistor 102 and current source internal to the pulse width modulation controller 100 , application of a control signal to pulse width modulation controller 100 , which either initiates a soft start or initiates a soft stop by pulse width modulation controller 100 .
- Control of the level of the application of the control signal to soft start input 106 allows proportional control of the respective timing of the rise and fall of voltages on the various power rails of power supply 10 .
- voltage levels on each of the power rails can be raised and lowered according to desired relative timing characteristics.
- Pulse width modulation controller 100 receives at a soft start input 106 either a control input to ramp up or ramp down power rail 22 associated with power converter 12 .
- a soft start refers to generation on the output rails of a power converter of a voltage ramp that grows to the desired output. In many cases the ramp is generally linear, but in others it may be non-linear.
- a soft stop refers to gradually terminating the voltage of the power rails in a converse fashion. Such gradual termination often takes the form of a linear ramp.
- a “rising ramp” refers to a general increasing signal, such as is applied during a soft start and a “falling ramp” refers to a generally decreasing signal, such as is applied during a soft stop. In both instances the ramp may be generally linear or non-linear.
- Additional circuitry 122 is provided to condition the output signal to generate a DC voltage level of 1.8 volts across nodes 22 and 24 , in this example. Other portions of power controller 12 are not explicitly shown.
- ramp circuit 101 includes a resistor 102 and a capacitor 104 .
- the time constants for a soft start are selected such that the highest voltage has the fastest turn on ramp rate.
- the soft stop time constants are selected such that the outputs are ramped down before the 12 volt supply is fully discharged, such that the highest voltage has the highest ramp down rate, and slow enough not to cause a resonance in the output inductance and output capacitance. This is due to excessive “on” time of the bottom side FET, creating a resonance between the output inductor and output capacitors. The resonance could otherwise cause uncontrolled excessively high or negative voltages and thus be destructive to the load.
- Other alternative ramp circuits may be utilized to properly apply a control signal to the respective soft start input 106 of each power controller utilizing a capacitor, constant current source, inductor, constant voltage source, resistor, or other ramp circuit topology.
- Pulse with modulation controller 100 may be any pulse with modulation controller having an analog soft start input capable of controlling the output voltage from less than 0.6 volts to the desired output voltage. This combination of ramp circuits results in a desired timing of the rise and fall of voltage levels produced by each of the power converters. In general, in this embodiment, the provided ramp circuits result in the lower DC power supplies rising slower and declining slower than the higher DC power supplies, although other relative timing characteristics are specified by selection of appropriate ramp rates.
- pulse width modulation controller 100 is an International Rectifier Model No. IRU3038.
- pulse width modulation controller 100 is operable to both source and sink voltages over rails 22 and 24 , respectively, and is a synchronous buck controller.
- a synchronous buck controller refers to a buck pulse width modulation controller operating both a high side FET and a low side FET.
- pulse width modulation controller 100 includes a plurality of input and output pins. Those pins include soft start input 106 , VCC input 108 , VC input 110 , HDRV pin 112 which provides a signal indicative of the output voltage at 22 , and LDRV output 114 , which provides a signal indicative of the output at node 24 .
- COMP pin 122 is a compensation pin utilized to stabilize a central loop.
- Feedback pin 124 receives feedback control as desired.
- VP (referring to program voltage) pin 126 receives a set point for the control loop. This allows setting of a set point of the power converter. The resulting output voltage is directly proportional to any voltage supplied to VP pin 126 .
- V ref receives a reference voltage. Operation of pulse width modulation controllers 100 are well within the knowledge of one skilled in the art and are not described in great detail here.
- FIG. 3 is a circuit diagram of voltage tracking and under voltage lockout circuit 52 .
- Circuit 52 includes an under voltage lockout circuit 202 coupled to voltage tracking circuit 203 .
- under voltage lockout circuit 202 monitors the voltage level applied at node 11 , the input power supplied to power supply 10 , and compares it to a reference voltage to determine whether power to power supply 106 is considered good. When power is considered to be good, in other words when the voltage level applied at node 11 is high enough, an indication to this effect is applied to voltage tracking circuit 203 .
- voltage tracking circuit 203 provides an indication over its respective output nodes 48 , 50 , 42 , 44 , and 46 to respective power converters 18 , 20 , 12 , 14 , and 16 , to begin a soft start sequence.
- circuitry illustrated in FIG. 3 may be replaced with other suitable circuitry for performing these functions.
- under voltage lockout circuit 202 includes a comparator 220 that compares a signal indicative of a reference voltage applied at an input node 216 to the voltage level on node 11 , supplied at the other input node 218 and generates an output signal on line 222 indicative of the difference.
- resistors 204 , 212 , 208 , 214 , 215 , and capacitors 206 and 224 are provided to select the desired threshold voltages.
- resistors 204 , 212 , 208 , 214 , 215 , and capacitors 206 and 224 are provided to select the desired threshold voltages.
- the output of comparator 220 is provided through a resistor 26 as inputs to the gates of n-type field effect transistors 230 , 232 , 234 , 236 , and 238 .
- transistors 230 , 232 , 234 , 236 , and 238 when the voltage levels on the respective gates of transistors 230 , 232 , 234 , 236 , and 238 are high, these transistors turn on and provide an output over nodes 48 , 50 , 42 , 44 , and 46 indicating the output voltage should be held off or soft stopped. Conversely, when the signals on these gates are low, an open circuit is supplied over the output nodes, indicating the output should soft start or be in a normal run mode.
- the voltage level supplied to power supply over node 11 is monitored by under voltage lockout portion 202 until it reaches its predetermined reference level close enough to twelve volts to be considered to be good.
- voltage tracking portion 203 initiates a soft start procedure with each respective power controller.
- the control signal provided to the soft start input 106 of each respective pulse width modulator 100 of each respective power controller is ramped by ramp circuit 101 , for an appropriate time. In this manner, ramping on of the power rails associated with each respective power controller is respectively ramped to generate desired voltage differences vs. time between power rail characteristics.
- voltage tracking circuit 203 acts conversely to initiate a soft stop through ramp circuit 101 .
- FIG. 4A is a circuit diagram illustrating one sided voltage differential protection circuit 54 of FIG. 1 .
- Voltage differential protection circuit 54 provides monitoring for an unexpected failure of the power supplies to be at the proper voltage. Voltage tracking would still happen normally if this section were omitted, provided there are no fault conditions within the power supplies.
- One sided voltage differential protection circuit 54 includes a monitoring portion 130 a and a voltage tracking portion 132 a .
- the operation of one sided voltage differential protection circuit 54 is analogous to the operation of under voltage lockout circuit 52 .
- voltage monitoring portion 130 a monitors the positive voltage differential between nodes 34 and 30 corresponding to power converters 18 and 16 .
- a signal is provided to the gates of the transistors within voltage tracking portion 132 a , which in turn initiate termination of a voltage to soft start pin 106 of each respective pulse width modulator controller 100 of the respective power converters, which in turn initiates a soft stop.
- the termination signal is supplied through a ramp circuit, such as circuit 101 , to effect relative timing of turning off the output voltages of each respective power converter.
- monitoring portion 130 a receives as inputs the output voltages at nodes 34 and 30 and provides signals indicative of the difference between the voltages to input nodes 148 and 150 of a comparator 146 .
- the output of comparator 146 is provided at node 152 and signals indicative of the output are provided on the gates of each of the transistors of voltage tracking circuit 132 a .
- Voltage tracking circuit 132 a is analogous to voltage tracking circuit 203 and operates in an analogous manner.
- the resistance ratio of resistors 134 , 136 , 138 , 140 , 142 A, and 154 sets the maximum allowable one sided voltage differential before asserting a fault condition.
- One sided voltage differential protection 130 A can be replicated, swapping power supply rails and reselecting resistors 134 , 136 , 138 , 140 , 142 A, and 154 to provide an indication of a negative voltage differential, instead of the positive voltage differential indicated in FIG. 4A .
- Voltage sequencing is a special case of voltage tracking, requiring an additional time delay on the rising edge of voltage tracking circuit 203 .
- the soft start input is not used, and VP pin 126 is ramped.
- FIG. 5 is a graph showing the rise and fall of voltage levels over example voltage rails according to the teachings of the invention. Illustrated in FIG. 5 is a graph showing a voltage versus time curve for the voltage levels at various portions of power supply 10 .
- Curve 250 illustrates the voltage over time characteristics of node 11 , which is the input voltage to power connectors 12 , 14 , 16 , 18 , and 20 .
- Curves 252 , 254 , and 256 illustrate the voltage over time characteristics at nodes 30 , 26 , and 34 , respectively, which correspond to the output nodes of power converters 16 , 14 , and 18 , corresponding to nominal voltage levels of 3.3 volts, 2.5 volts, and 1.35 volts, respectively. These voltage levels comply with the desired characteristics described above.
- FIG. 6 is a method for controlling voltages in a power supply.
- the method begins at step 310 .
- a plurality of DC to DC power converters having a pulse width modulator controller with soft start input and source sink capability are provided, in one embodiment.
- the method detects when an input power supply to power controller reaches a particular voltage level exceeding an under voltage lockout threshold.
- analog control signals are provided to each respective soft start input such that each respective power converter generates desired voltage level over time characteristics.
- Step 340 may include providing respective signals through respective ramp circuits having desired time constants.
- Step 350 the voltage differential between one or more of the pairs of the power converters is monitored and upon detection of a voltage differential exceeding a threshold, power to each of the soft start inputs of the power converters is terminated in a ramp sequence such that each respective power converter generates desired voltage levels over time characteristics.
- Step 350 may include providing a control signal to a soft start input of each power controller through a ramp circuit having desired time constant. Such ramp circuits may be different or the same to ramp circuits as those utilized in step 340 .
- the power supplied to the power supply may be monitored for an input power bad condition.
- soft stops may be initiated by providing the appropriate control signals to the respective soft start inputs of the various power converters. The method concludes at step 370 .
- desired voltage versus time characteristics may be maintained both during startup and shut down of the power supply, including monitoring for undesirable voltage differentials, and upon detection, shutting down the power supply while maintaining desired shut down sequencing and tracking, preventing any damage to delicate load integrated circuits due to improper power supply start up or shutdown.
Abstract
A method for controlling multiple voltages in a power supply includes providing a plurality of DC to DC power converters. Each power converter includes a pulse width modulator controller having a control pin. The method also includes when a voltage supply to the power controllers reads a particular level. After the particular level is met, the method includes providing a respective rising ramp control signal to each respective control pin of the pulse width modulator controller such that each respective power converter generates desired voltage level over time characteristics.
Description
- This application is a continuation of U.S. applicaton Ser. No. 10/443,911 filed May 21, 2003 and entitled “Method and System for Voltage Tracking and Sequencing in a Power Supply”.
- This invention relates generally to power supplies and more particularly to a method and system for voltage tracking and sequencing in a power supply.
- Power supplies are required in most every electronic device used today. An example use of a power supply is in an Ethernet switch. Such power supplies often require multiple different power levels for various portions of the Ethernet switch. A given power level is sometimes referred to as a power rail. Such power supplies often receive one voltage level as an input, such as 12 volts and generate numerous different power levels through a plurality of power converters.
- It is known that in such a power supply problems arise if the voltage levels generated by each of the power converters rise to their full level, or drop to zero upon termination, such that particular differential voltage levels between any two of the power rails reach undesired levels. Thus, techniques have been developed for both controlling the order at which power rails come up to power or terminate power, referred to as voltage sequencing, as well as controlling the relative voltage differential between any two power rails, referred to a voltage tracking. Various approaches include series element control, shunt element control, clamp diodes, enabling a lower voltage rail in response to a power good signal, and feedback based control. Each of these methods has disadvantages.
- Series element control involves a voltage tracking controller, large series pass field effect transistors, and a set of multiple power supplies. The voltage tracking controller senses the output voltage and linearly controls the gate voltage to the series pass field effect transistors. This requires the series pass field effect transistors to be able to pass the entire load of the power rail with minimal voltage drop. This approach can be expensive, reduce reliability, generate heat, and consume board real estate.
- Shunt element control involves monitoring a voltage delta between two rails and linearly controlling the gate from a field effect transistor shorting the two rails. The field effect transistor must be capable of handling large currents associated with shorting high current rails. Power is dissipated only during start up and shut down, unlike the series element method.
- The use of clamp diodes involves simply attaching a Schottky diode between power rails. If the higher voltage rail falls below the lower rail, the load of the lower rail is increased to bring the rails down together. This approach has a problem of possible overloading of the lower voltage supply, causing undue stress. It also requires diodes large enough to clamp the rails together. The diodes are physically large and costly.
- In the fourth approach, a power good signal may be used to enable a lower voltage rail. This solution is suitable for voltage sequencing, but not useful for voltage tracking. A large number of small logical elements is required.
- In a feedback based control approach, a resistor divider is used off of a higher voltage rail to generate a reference for the lower voltage rail pulse width modulator. A lower voltage reference ramps up or down to follow the upper rail. This feature does not accommodate voltage margining.
- A method for controlling multiple voltages in a power supply includes providing a plurality of DC to DC power converters. Each power converter includes a pulse width modulator controller having a control pin. The method also includes detecting when a voltage supply to the power controllers reaches a particular level. After the particular level is met, the method includes providing a respective rising ramp control signal to each respective control pin of the pulse width modulator controller such that each respective power converter generates desired voltage level over time characteristics.
- Some embodiments of the invention provide numerous technical advantages. Some embodiments may benefit from some, none, or all of these advantages. According to one embodiment, voltage tracking and sequencing may be achieved while still allowing voltage margining, which is desirable. In addition, according to one embodiment of the invention, voltage tracking and sequencing may be performed using relatively inexpensive devices and wasting virtually no power.
- Other technical advantages may be readily ascertained by one of skill in the art.
- Reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numbers represent like parts, in which:
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FIG. 1 is a block diagram illustrating portions of a power supply according to the teachings of the invention; -
FIG. 2 is a circuit diagram illustrating portions of each of the power converters ofFIG. 1 ; -
FIG. 3 is a circuit diagram illustrating the voltage tracking and sequencing circuit ofFIG. 1 ; -
FIG. 4A is a circuit diagram illustrating a voltage differential protection circuit ofFIG. 1 ; -
FIG. 4B is a circuit diagram illustrating a second voltage protection circuit ofFIG. 1 ; -
FIG. 4C is a circuit diagram illustrating a third voltage protection circuit ofFIG. 1 ; -
FIG. 5 is a graph of voltage versus time illustrating the rise and fall of power rails of the power supply ofFIG. 1 ; and -
FIG. 6 is a flowchart illustrating a method for controlling voltage levels in a power converter. - Embodiments of the invention are best understood by referring to
FIGS. 1 through 6 of the drawings, like numerals being used for like and corresponding parts of the various drawings. -
FIG. 1 is a block diagram illustrating portions of apower supply 10 according to the teachings of the invention.Power supply 10 includes a plurality ofpower converters Power converter 12converts 12 volts DC to 1.8 volts DC.Power controller 14converts 12 volts DC to 2.5 volts DC.Power controller 16converts 12 volts DC to 3.3 volts DC.Power controller 18converts 12 volts DC to 1.35 volts DC.Power controller 20converts 12 volts DC to 1.5 volts DC. However, the teachings of the invention are applicable to any suitable number of converters as well as any levels of power conversion. - Each power converter receives as input twelve volts at a
respective node 11 and generates a voltage at its outputnode. Power converter 12 generates 1.8 volt onoutput nodes 22.Power converter 14 generates 2.5 volts onoutput nodes 26.Power converter 16 generates 3.3 volts acrossnodes 30.Power converter 18 generates 1.35 volts onnode 34.Power converter 20 generates 1.5 volts onnode 38. The output node of each power converter is also referred to as a power rail. - Also included in
power supply 10 is a voltage tracking and undervoltage lockout circuit 52, and a plurality of voltagedifferential protection circuits voltage lockout circuit 52 includes avoltage tracking circuit 203 and an under-voltage lockout circuit 202, as illustrated inFIG. 3 . In the illustrated embodiment,voltage tracking circuit 203 receives a digital input from undervoltage lockout circuit 202 and from voltagedifferential protection circuits - Under
voltage lockout circuit 202 monitors a nominal 12 volt power supply atnode 11, and based upon the detected actual level outputs appropriate control signals overlines FIG. 3 . In general, however, undervoltage lockout circuit 202 detects when the supplied voltage provided atnode 11 reaches a predetermined level and in response initiates turning on of the power converters by providing appropriate voltage levels to each of thepower converters voltage lockout circuit 202 initiates turning off the power converters when it determines the supplied voltage is too low. - Each of voltage
differential protection circuits differential protection circuit 54monitors nodes power converters differential protection circuit 56monitors nodes power converters differential protection circuit 58monitors nodes power converters FIGS. 3A-3C . Generally, however, upon detection of a specified voltage differential between the monitored power rails of a particular pair of power converters, a control signal is transmitted to each respective power controller overlines protection circuit 54 indicating each power converter should shut down in an orderly fashion to maintain tracking requirements, thereby avoiding undesirable differential voltages, which could lead to damaged load integrated circuits. Control signals are transmitted overlines protection circuit 56. Control signals are transmitted overlines protection circuit 58. - As described in greater detail below, both control signals transmitted to
power converters circuit 52 as well as control signals topower converters differential protection circuits power converters FIGS. 2 through 6 . -
FIG. 2 is a circuit diagram of portions ofpower controller 12, as an example.Power controllers power controller 12, with the differences described below.Power converter 12 includes aramp circuit 101, a pulsewidth modulation controller 100, andadditional circuitry 122. In general,ramp circuit 101 receives input atnode 42 fromvoltage tracking circuit 203, which is controlled by undervoltage lockout circuit 202, as well as voltagedifferential protection circuits soft start pin 106. Forpower controller 14, the corresponding ramp circuit receives input atnode 44; forpower controller 16, the corresponding ramp circuit receives input atnode 46; forpower controller 18, the corresponding ramp circuit receives input atnode 48; and forpower controller 20, the corresponding ramp circuit receives input atnode 50. -
Ramp circuit 101 ramps, for a particular time constant determined predominantly bycapacitor 104,resistor 102 and current source internal to the pulsewidth modulation controller 100, application of a control signal to pulsewidth modulation controller 100, which either initiates a soft start or initiates a soft stop by pulsewidth modulation controller 100. Control of the level of the application of the control signal tosoft start input 106 allows proportional control of the respective timing of the rise and fall of voltages on the various power rails ofpower supply 10. By utilizing various levels of capacitance forcapacitor 104 andresistance 102 in each of the power controllers, voltage levels on each of the power rails can be raised and lowered according to desired relative timing characteristics. - Pulse
width modulation controller 100 receives at asoft start input 106 either a control input to ramp up or ramp downpower rail 22 associated withpower converter 12. A soft start refers to generation on the output rails of a power converter of a voltage ramp that grows to the desired output. In many cases the ramp is generally linear, but in others it may be non-linear. A soft stop refers to gradually terminating the voltage of the power rails in a converse fashion. Such gradual termination often takes the form of a linear ramp. As used herein a “rising ramp” refers to a general increasing signal, such as is applied during a soft start and a “falling ramp” refers to a generally decreasing signal, such as is applied during a soft stop. In both instances the ramp may be generally linear or non-linear. -
Additional circuitry 122 is provided to condition the output signal to generate a DC voltage level of 1.8 volts acrossnodes power controller 12 are not explicitly shown. - As illustrated,
ramp circuit 101 includes aresistor 102 and acapacitor 104. In general, in one embodiment, the time constants for a soft start are selected such that the highest voltage has the fastest turn on ramp rate. The soft stop time constants are selected such that the outputs are ramped down before the 12 volt supply is fully discharged, such that the highest voltage has the highest ramp down rate, and slow enough not to cause a resonance in the output inductance and output capacitance. This is due to excessive “on” time of the bottom side FET, creating a resonance between the output inductor and output capacitors. The resonance could otherwise cause uncontrolled excessively high or negative voltages and thus be destructive to the load. Other alternative ramp circuits may be utilized to properly apply a control signal to the respectivesoft start input 106 of each power controller utilizing a capacitor, constant current source, inductor, constant voltage source, resistor, or other ramp circuit topology. - Pulse with
modulation controller 100 may be any pulse with modulation controller having an analog soft start input capable of controlling the output voltage from less than 0.6 volts to the desired output voltage. This combination of ramp circuits results in a desired timing of the rise and fall of voltage levels produced by each of the power converters. In general, in this embodiment, the provided ramp circuits result in the lower DC power supplies rising slower and declining slower than the higher DC power supplies, although other relative timing characteristics are specified by selection of appropriate ramp rates. In one embodiment, pulsewidth modulation controller 100 is an International Rectifier Model No. IRU3038. In addition, in one embodiment, pulsewidth modulation controller 100 is operable to both source and sink voltages overrails width modulation controller 100 includes a plurality of input and output pins. Those pins includesoft start input 106,VCC input 108,VC input 110,HDRV pin 112 which provides a signal indicative of the output voltage at 22, andLDRV output 114, which provides a signal indicative of the output atnode 24. APGNP input 116, aground input 118, anRT pin 120, aCOMP pin 122, afeedback pin 124, aVP pin 126, and aV ref pin 128.COMP pin 122 is a compensation pin utilized to stabilize a central loop.Feedback pin 124 receives feedback control as desired. VP (referring to program voltage)pin 126 receives a set point for the control loop. This allows setting of a set point of the power converter. The resulting output voltage is directly proportional to any voltage supplied toVP pin 126. V ref receives a reference voltage. Operation of pulsewidth modulation controllers 100 are well within the knowledge of one skilled in the art and are not described in great detail here. -
FIG. 3 is a circuit diagram of voltage tracking and undervoltage lockout circuit 52.Circuit 52 includes an undervoltage lockout circuit 202 coupled tovoltage tracking circuit 203. In general, undervoltage lockout circuit 202 monitors the voltage level applied atnode 11, the input power supplied topower supply 10, and compares it to a reference voltage to determine whether power topower supply 106 is considered good. When power is considered to be good, in other words when the voltage level applied atnode 11 is high enough, an indication to this effect is applied tovoltage tracking circuit 203. In response,voltage tracking circuit 203 provides an indication over itsrespective output nodes respective power converters FIG. 3 may be replaced with other suitable circuitry for performing these functions. - In this example, under
voltage lockout circuit 202 includes acomparator 220 that compares a signal indicative of a reference voltage applied at aninput node 216 to the voltage level onnode 11, supplied at theother input node 218 and generates an output signal online 222 indicative of the difference. In performing such a function,resistors capacitors comparator 220 is provided through aresistor 26 as inputs to the gates of n-typefield effect transistors transistors nodes - In operation, the voltage level supplied to power supply over
node 11, normally twelve volts in this embodiment, is monitored by undervoltage lockout portion 202 until it reaches its predetermined reference level close enough to twelve volts to be considered to be good. At such a time,voltage tracking portion 203 initiates a soft start procedure with each respective power controller. As described above, the control signal provided to thesoft start input 106 of each respectivepulse width modulator 100 of each respective power controller is ramped byramp circuit 101, for an appropriate time. In this manner, ramping on of the power rails associated with each respective power controller is respectively ramped to generate desired voltage differences vs. time between power rail characteristics. Conversely, whenpower supply 10 is operating but the voltage provided atnode 11 is determined not to be above the specified level (power bad),voltage tracking circuit 203 acts conversely to initiate a soft stop throughramp circuit 101. -
FIG. 4A is a circuit diagram illustrating one sided voltagedifferential protection circuit 54 ofFIG. 1 . Voltagedifferential protection circuit 54 provides monitoring for an unexpected failure of the power supplies to be at the proper voltage. Voltage tracking would still happen normally if this section were omitted, provided there are no fault conditions within the power supplies. One sided voltagedifferential protection circuit 54 includes a monitoring portion 130 a and a voltage tracking portion 132 a. The operation of one sided voltagedifferential protection circuit 54 is analogous to the operation of undervoltage lockout circuit 52. In general, voltage monitoring portion 130 a monitors the positive voltage differential betweennodes power converters soft start pin 106 of each respective pulsewidth modulator controller 100 of the respective power converters, which in turn initiates a soft stop. As described above, the termination signal is supplied through a ramp circuit, such ascircuit 101, to effect relative timing of turning off the output voltages of each respective power converter. Although a particular circuit is provided, any suitable circuitry that performs the same or similar functions may be utilized. - In this particular example, monitoring portion 130 a receives as inputs the output voltages at
nodes nodes comparator 146. The output ofcomparator 146 is provided atnode 152 and signals indicative of the output are provided on the gates of each of the transistors of voltage tracking circuit 132 a. Voltage tracking circuit 132 a is analogous tovoltage tracking circuit 203 and operates in an analogous manner. In protection circuit 130 a, the resistance ratio ofresistors - One sided
voltage differential protection 130A can be replicated, swapping power supply rails andreselecting resistors FIG. 4A . - Voltage sequencing is a special case of voltage tracking, requiring an additional time delay on the rising edge of
voltage tracking circuit 203. - In an alternate embodiment, the soft start input is not used, and
VP pin 126 is ramped. -
FIG. 5 is a graph showing the rise and fall of voltage levels over example voltage rails according to the teachings of the invention. Illustrated inFIG. 5 is a graph showing a voltage versus time curve for the voltage levels at various portions ofpower supply 10.Curve 250 illustrates the voltage over time characteristics ofnode 11, which is the input voltage topower connectors Curves nodes power converters -
FIG. 6 is a method for controlling voltages in a power supply. The method begins atstep 310. At step 320 a plurality of DC to DC power converters having a pulse width modulator controller with soft start input and source sink capability are provided, in one embodiment. Atstep 330 the method detects when an input power supply to power controller reaches a particular voltage level exceeding an under voltage lockout threshold. At astep 340, after the particular level is met analog control signals are provided to each respective soft start input such that each respective power converter generates desired voltage level over time characteristics. Step 340 may include providing respective signals through respective ramp circuits having desired time constants. Atstep 350, the voltage differential between one or more of the pairs of the power converters is monitored and upon detection of a voltage differential exceeding a threshold, power to each of the soft start inputs of the power converters is terminated in a ramp sequence such that each respective power converter generates desired voltage levels over time characteristics. Step 350 may include providing a control signal to a soft start input of each power controller through a ramp circuit having desired time constant. Such ramp circuits may be different or the same to ramp circuits as those utilized instep 340. - Additionally, at
step 360, the power supplied to the power supply may be monitored for an input power bad condition. Upon detection of a power bad condition, soft stops may be initiated by providing the appropriate control signals to the respective soft start inputs of the various power converters. The method concludes atstep 370. - Thus, according to this method of the invention, desired voltage versus time characteristics may be maintained both during startup and shut down of the power supply, including monitoring for undesirable voltage differentials, and upon detection, shutting down the power supply while maintaining desired shut down sequencing and tracking, preventing any damage to delicate load integrated circuits due to improper power supply start up or shutdown.
- Although some embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (30)
1. A method for controlling multiple voltages in a power supply comprising:
providing a plurality of DC to DC power converters each having a pulse width modulator controller having a control pin;
detecting when a voltage supply to the power converters reaches a particular level; and
after the particular level is met, initiating turning on or turning off of the respective power converter by providing a respective rising ramp control signal to each respective control pin of the pulse width modulator controller such that each respective power converter generates desired voltage level over time characteristics according to a desired voltage differential with respect to the other power converters.
2. The method of claim 1 , wherein the control pin is a soft start pin.
3. The method of claim 1 , wherein the control pin is a pin operable to receive a set point for the pulse width modulator controller.
4. The method of claim 1 , wherein the ramp control signals are generated by respective circuits having desired time constants.
5. The method of claim 1 , and further comprising, for at least one pair of the plurality of power converters, monitoring a voltage differential between the voltages generated by each power converter in the pair and, upon detection of a particular differential voltage level providing a falling ramp control signal to the soft start input of each of the power converters that initiates a soft stop such that each respective power converter generates desired voltage level over time characteristics.
6. The method of claim 5 , wherein the falling ramp control signal is provided to the soft start input of each of the power converters by respective ramp circuits having desired time constants.
7. The method of claim 2 , and further comprising, for at least one pair of the plurality of power converters, monitoring a voltage differential between the voltages generated by each power converter in the pair and, upon detection of a particular differential voltage level, providing a falling ramp control signal to the soft start input of each of the power converters that initiates a soft stop such that each respective power converter generates desired voltage level over time characteristics.
8. The method of claim 7 , wherein the falling ramp control signal is provided to the soft start input of each of the power converters by the respective ramp circuits having desired time constants.
9. The method of claim 2 , and further comprising:
monitoring the voltage supply to the pulse width modulator controller;
detecting when the voltage supply falls below a specific level; and
in response to detecting when the voltage supply falls below a specified level, providing a falling ramp control signal to each respective soft start input such that each respective power converter generates desired voltage level over time characteristics.
10. The method of claim 7 , wherein the falling ramp control signals are provided to the soft start input of each of the power converters through respective ramp circuits having desired time constraints.
11. An apparatus for controlling multiple voltages in a power supply comprising:
a plurality of DC to DC power converters each having a pulse-width-modulator controller having a control pin;
a detection means for detecting when an input voltage supply to the power controller reaches a particular level; and
a ramping means for initiating turning on or turning off of the respective power converter by providing a rising ramp control signal to each control pin such that each respective power converter generates desired voltage over time characteristics according to a desired voltage differential with respect to the other power converters.
12. The apparatus of claim 11 , wherein the control pin is a soft start pin.
13. The apparatus of claim 11 , wherein the control pin is pin operable to receive a set point for the controller.
14. The apparatus of claim 9 , and further comprising, for at least one pair of the plurality of power converters, a voltage differential means for monitoring the voltages generated by each power converter in the pair, and, upon detection of a particular voltage differential, providing a falling ramp control signal to the control pin of each of the power converters to initiate a soft stop.
15. The apparatus of claim 11 , further comprising a voltage ramping means for controlling tracking of the termination of the voltage supplied to the control pin of each of the power converters.
16. The apparatus of claim 15 , wherein the ramping means and the voltage differential ramping means are different means.
17. A power supply comprising:
a plurality of DC to DC power converters, each having a pulse width modulation controller having a soft start switch;
a voltage tracking and under voltage lockout circuit operable to determine when a voltage level supplied to the power controller reaches predetermined levels and in response provide first control signals to each respective soft start input of the power converter;
at least one voltage differential protection circuit operable to detect a voltage differential between voltages generated by a respective pair of the power converters, determine whether the detected voltage level meets specific criteria, and in response provide an appropriate control signal to the soft start switch of each power converter;
a plurality of respective ramp circuits associated with respective ones of the power converters, each ramp circuit operable to:
receive respective control signals from the voltage tracking and under voltage lockout circuit and initiate turning on or turning off of the respective power converter by providing a rising ramp control signal to each respective soft start input of the power converters according to a time constant of the ramp circuit; and
receive respective voltage levels from the at least one voltage differential protection circuit and delay providing the second control signals to the soft start switch of the respective power converter according to a time constant of the ramp circuit to achieve a desired voltage differential with respect to the other power converters.
18. The power supply of claim 17 , wherein the plurality of respective ramp circuits each comprise an RC circuit.
19. The power supply of claim 18 , wherein each of the plurality of respective ramp circuits have a different ramp rate than any of the other ramp circuits such that either of the first or second control signals are provided to each of the power converters at a different rate.
20. The power supply of claim 17 , wherein the plurality of DC power converters comprises five power converters.
21. The power supply of claim 20 , wherein the five power converters comprise a 12 volt to 1.8 volt power converter, a 12 volt to 2.5 volt power converter, a 12 volt to 3.3 volt power converter, a 12 volt to 1.35 volt power converter, and a 12 volt to 1.5 volt power converter.
22. The power supply of claim 17 , wherein the at least one voltage differential protection circuit comprises three voltage differential protection circuits, one of the three voltage differential protection circuits monitoring a voltage differential between the 12 volt to 3.3 volt power converter and the 1.35 volt power converter, a second voltage protection circuit monitoring the voltage differential between the 12 volt to 3.3 volt power converter and the 12 volt to 2.5 volt power converter, and a third voltage differential protection circuit monitoring the voltage differential between the 12 volt to 2.5 volt power converter and the 12 volt to 1.8 volt power converter.
23. The power supply of claim 17 , wherein the voltage tracking circuit comprises a plurality of field effect transistors for selectively providing the first control signals to the respective power converters.
24. The power supply of claim 17 , wherein the plurality of respective voltage differential detection circuits and a plurality of transistors each operable to selectively transmit control signals to the soft start input of each power converter.
25. A power supply regulator comprising:
a plurality of DC to DC power converters, each having a pulse width modulation controller having a soft start pin;
a voltage tracking and under voltage lockout circuit operable to determine when a voltage level supplied to the power controller reaches a predetermined threshold and in response provide control signals to each respective soft start input of the power converter;
a plurality of respective ramp circuits associated with respective ones of the power converters, each ramp circuit operable to receive respective control signals from the voltage tracking and voltage lockout circuit and initiate turning on or turning off of the respective power converter by providing a respective rising ramp control signal to each respective soft start input of the power converter according to a time constant of the ramp circuit according to a desired voltage differential with respect to the other power converters.
26. The power supply of claim 25 , wherein the plurality of respective ramp circuits each comprise an RC circuit.
27. The power supply of claim 26 , wherein the plurality of respective ramp circuits each have a different ramp time constant such that the control signal is provided to each of the power converters at a different rate operable to produce a minimal voltage delta during power supply turn on or power supply turn off.
28. The power supply of claim 21 , wherein the plurality of DC power converters comprises five power converters.
29. The power supply of claim 28 , wherein the five power converters comprise a 12 volt to 1.8 volt power converter, a 12 volt to 2.5 volt power converter, a 12 volt to 3.3 volt power converter, a 12 volt to 1.35 volt power converter, and a 12 volt to 1.5 volt power converter.
30. The power supply of claim 25 , wherein the ramp circuit is coupled to an under voltage lockout circuit.
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US11/531,165 US20070001514A1 (en) | 2003-05-21 | 2006-09-12 | Method and System for Voltage Tracking and Sequencing in a Power Supply |
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US10/443,911 US7105947B1 (en) | 2003-05-21 | 2003-05-21 | Method and system for voltage tracking and sequencing in a power supply |
US11/531,165 US20070001514A1 (en) | 2003-05-21 | 2006-09-12 | Method and System for Voltage Tracking and Sequencing in a Power Supply |
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US10/443,911 Continuation US7105947B1 (en) | 2003-05-21 | 2003-05-21 | Method and system for voltage tracking and sequencing in a power supply |
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US20070001514A1 true US20070001514A1 (en) | 2007-01-04 |
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US10/443,911 Expired - Fee Related US7105947B1 (en) | 2003-05-21 | 2003-05-21 | Method and system for voltage tracking and sequencing in a power supply |
US11/531,165 Abandoned US20070001514A1 (en) | 2003-05-21 | 2006-09-12 | Method and System for Voltage Tracking and Sequencing in a Power Supply |
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US10/443,911 Expired - Fee Related US7105947B1 (en) | 2003-05-21 | 2003-05-21 | Method and system for voltage tracking and sequencing in a power supply |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
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US20120153992A1 (en) * | 2010-12-17 | 2012-06-21 | Texas Instruments Incorporated | Analog power sequencer and method |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
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Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3740569A (en) * | 1971-08-26 | 1973-06-19 | Integrated Sys Technology Inc | Direct-current power supply system |
US4488060A (en) * | 1979-01-24 | 1984-12-11 | Xicor, Inc. | High voltage ramp rate control systems |
US4652769A (en) * | 1984-02-14 | 1987-03-24 | Ion Tech, Inc. | Module power supply |
US4733389A (en) * | 1986-07-28 | 1988-03-22 | Xerox Corporation | Drop cable for a local area network |
US5307001A (en) * | 1992-05-05 | 1994-04-26 | Dimensions Unlimited, Inc. | Battery charging method and apparatus |
US5324989A (en) * | 1992-12-17 | 1994-06-28 | Thornton Roger D | Power controller module providing user selectable overload protection |
US5406260A (en) * | 1992-12-18 | 1995-04-11 | Chrimar Systems, Inc. | Network security system for detecting removal of electronic equipment |
US5534768A (en) * | 1994-02-09 | 1996-07-09 | Harris Corporation | Regulated power supply having wide input AC/DC voltage range |
US5811962A (en) * | 1997-02-27 | 1998-09-22 | International Business Machines Corporation | Power supply control circuit |
US5952733A (en) * | 1997-12-05 | 1999-09-14 | Intel Corporation | Power distribution system for electronic devices |
US6429706B1 (en) * | 2000-12-05 | 2002-08-06 | Juniper Networks, Inc. | Voltage sequencing circuit for powering-up sensitive electrical components |
US6459275B1 (en) * | 2001-02-28 | 2002-10-01 | Avaya Technology Corp. | Detection of devices on a local area network |
US6462438B1 (en) * | 2000-09-27 | 2002-10-08 | Intel Corporation | Supply voltage sequencing |
US6771052B2 (en) * | 2003-01-03 | 2004-08-03 | Astec International Limited | Programmable multiple output DC-DC isolated power supply |
US6841897B2 (en) * | 2002-06-03 | 2005-01-11 | Adc Dsl Systems, Inc. | Input power sharing |
US6897636B2 (en) * | 2002-03-29 | 2005-05-24 | Intersil Americas Inc. | Method and circuit for scaling and balancing input and output currents in a multi-phase DC-DC converter using different input voltages |
-
2003
- 2003-05-21 US US10/443,911 patent/US7105947B1/en not_active Expired - Fee Related
-
2006
- 2006-09-12 US US11/531,165 patent/US20070001514A1/en not_active Abandoned
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3740569A (en) * | 1971-08-26 | 1973-06-19 | Integrated Sys Technology Inc | Direct-current power supply system |
US4488060A (en) * | 1979-01-24 | 1984-12-11 | Xicor, Inc. | High voltage ramp rate control systems |
US4652769A (en) * | 1984-02-14 | 1987-03-24 | Ion Tech, Inc. | Module power supply |
US4733389A (en) * | 1986-07-28 | 1988-03-22 | Xerox Corporation | Drop cable for a local area network |
US5307001A (en) * | 1992-05-05 | 1994-04-26 | Dimensions Unlimited, Inc. | Battery charging method and apparatus |
US5324989A (en) * | 1992-12-17 | 1994-06-28 | Thornton Roger D | Power controller module providing user selectable overload protection |
US5406260A (en) * | 1992-12-18 | 1995-04-11 | Chrimar Systems, Inc. | Network security system for detecting removal of electronic equipment |
US5534768A (en) * | 1994-02-09 | 1996-07-09 | Harris Corporation | Regulated power supply having wide input AC/DC voltage range |
US5811962A (en) * | 1997-02-27 | 1998-09-22 | International Business Machines Corporation | Power supply control circuit |
US5952733A (en) * | 1997-12-05 | 1999-09-14 | Intel Corporation | Power distribution system for electronic devices |
US6462438B1 (en) * | 2000-09-27 | 2002-10-08 | Intel Corporation | Supply voltage sequencing |
US6429706B1 (en) * | 2000-12-05 | 2002-08-06 | Juniper Networks, Inc. | Voltage sequencing circuit for powering-up sensitive electrical components |
US6459275B1 (en) * | 2001-02-28 | 2002-10-01 | Avaya Technology Corp. | Detection of devices on a local area network |
US6897636B2 (en) * | 2002-03-29 | 2005-05-24 | Intersil Americas Inc. | Method and circuit for scaling and balancing input and output currents in a multi-phase DC-DC converter using different input voltages |
US6841897B2 (en) * | 2002-06-03 | 2005-01-11 | Adc Dsl Systems, Inc. | Input power sharing |
US6771052B2 (en) * | 2003-01-03 | 2004-08-03 | Astec International Limited | Programmable multiple output DC-DC isolated power supply |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100906603B1 (en) * | 2007-06-11 | 2009-07-09 | 주식회사 다산네트웍스 | Power providing apparatus with the ability of settling a moment power failure problem |
US20120153992A1 (en) * | 2010-12-17 | 2012-06-21 | Texas Instruments Incorporated | Analog power sequencer and method |
US8680710B2 (en) * | 2010-12-17 | 2014-03-25 | Texas Instruments Incorporated | Analog power sequencer and method |
US20130127429A1 (en) * | 2011-11-21 | 2013-05-23 | Ciou-Fong Li | Soft-stop Device and Power Converter Using the Same |
EP3503334A1 (en) * | 2017-12-20 | 2019-06-26 | Delphi International Operations Luxembourg S.à r.l. | A power supply unit for an electronic device |
CN109980939A (en) * | 2017-12-20 | 2019-07-05 | Aptiv技术有限公司 | Power supply unit for electronic device |
US11216056B2 (en) * | 2017-12-20 | 2022-01-04 | Aptiv Technologies Limited | Power supply unit for an electronic device |
EP4057108A1 (en) * | 2017-12-20 | 2022-09-14 | Aptiv Technologies Limited | A power supply unit for an electronic device |
US20210365098A1 (en) * | 2020-05-20 | 2021-11-25 | Nxp Usa, Inc. | Safety monitoring or power-up and/or power-down of a power management device |
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