TW565987B - Balanced current converter with multiple pulse width modulated channels - Google Patents

Abstract

A balanced current converter with multiple PWM converter channels is described. A balanced current converter has an error amplifier, a main converter channel and at least one parallel converter channel. The converter provides a DC power output and feeds back an average output voltage signal. The error amplifier compares the reference voltage signal and the average output voltage signal to generate the error signal. The main converter channel outputs the main channel current signal and the main channel power output according to the error signal. The parallel converter channel compares the main channel current signal and the respective parallel channel current signal to generate the first deviation signal. The parallel converter channel continues comparing the first deviation signal and the error signal to generate a second deviation signal. The parallel converter channel provides a respective parallel channel power output and measures the respective parallel channel power output to feed back the respective parallel channel current signal. Therefore, each parallel converter channel adjusts the parallel channel power output thereof according to the main channel current signal, the error signal and the feedback of the respective parallel channel current signal. Therefore, the converter according to the invention provides a stable voltage output and a balanced current output with a simple control circuit. The converter may turn off some parallel converter channels and adjust and share the total output current with the working channels equally and automatically.

Description

565987 A7 B7 V. Description of the Invention () Field of the Invention: Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economics This invention relates to a power converter, in particular to a multi-channel pulse width modulation converter with balanced current . Background of the Invention: With the new generation of computers' requirements for high speed and high current, especially the current requirements of the microprocessor of the latest personal computer (PC), has exceeded 60 amps (A), so the DC-DC converter's Current requirements are also increasing. Therefore, the architecture of multi-channel parallel converters is often cited. Among them, multi-phase multi-channel converters can use smaller and cheaper filter capacitors because of the dispersion of the input and output current ripples. Multi-channel parallel converters use several Pulse-width Modulated conversion channels with the same output power, and connect their output terminals in parallel to provide higher output current. In several channels, due to the unavoidable slight asymmetry between the channels, one or more channels will bear a higher load disproportionately. What's more, if each channel is a synchronous rectified form with sinking and Sourcing current capabilities, a huge reactive current may flow from a channel with a high voltage to a channel with a low voltage, causing additional Power consumption, and cause uneven work burden of the power components of each channel, so the power 3

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Order · 565987 Α7

V. Description of the invention () However, when the number of working channels to be used is changed, the circuit of this converter needs to modify its average circuit 'to obtain a suitable average channel current value. How to provide a multi-channel power converter and simply and effectively distribute the load current evenly to each parallel working channel is an important development direction of a multi-channel power converter. Object and Summary of the Invention: In the background of the invention mentioned above, because the current demand of the new PC microprocessor increases, the converter capable of providing a large current is needed. How to provide a multi-channel power converter, easily and effectively distribute the load current evenly to each conversion channel, and the number of conversion channels can be adjusted according to the needs of use, which provides important information for multi-channel power converters. contribution. One of the objects of the present invention is to provide a converter with balanced output current of each conversion channel, which can achieve the purpose of stabilizing voltage output and balancing current output of each channel. Another object of the present invention is to provide a power converter with a balanced current function which can be used not only for single-phase power conversion but also for multi-phase power conversion. According to the above-mentioned purpose, the present invention is a multi-channel pulse width modulation converter with balanced current, which includes an error amplifier. The reference voltage of the standard output is compared with the average output voltage of the converter, and the Z converter is input. Voltage difference signal to control the main conversion channel and multiple parallel conversions. This paper size is applicable to China National Standard (CNS) A4 specification (210X297) ------ f Please read the precautions on the back before filling this page}- I: b Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565987 A7 _ V. Description of the invention () The preferred embodiment of the present invention will be supplemented by the following figures in the following explanatory text for more detailed explanation, of which : The first picture is a conventional multi-channel parallel-channel DC converter; and the second picture is a multi-channel pulse width modulation converter with balanced current according to the present invention. (Please read the precautions on the back before filling in this page)

Printed by Rongdian of the Intellectual Property Bureau of the Ministry of Economic Affairs, Consumer Cooperatives 3 2 Detailed descriptions and detailed drawing numbers Contrast description: 101 Error amplifier 102 Adding circuit 103 Proportional circuit 104 Subtraction circuit 105 Compensation circuit 106 Subtraction circuit 107 Pulse width modulator 108 Power switch 109 Inductor 110 Current detector 111 Load 112 Capacitor 201 to 204 Pulse width modulator 205 to 208 Power switch 209 to 212 Inductor 213 to 2 1 6 Current sense resistor 217 to 220 Differential circuit 221 to 226 Subtraction Circuits 227 to 229 Compensation circuit 230 Error amplifier This paper size is applicable to Chinese National Standard (CNS) A4 specification (210 × 297 mm) 565987 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention () From the background of the invention It can be seen that the current requirements of the latest Pc microprocessors have exceeded 60 amps, so a DC-DC converter capable of providing high current is needed. The multi-channel parallel converter architecture can use smaller and cheaper filter capacitors due to the dispersion of the input and output current ripple. However, the conventional converter 'because of the unavoidable asymmetric voltage, one or more channels will be disproportionately subjected to the load, resulting in additional power consumption, and the rated tolerance of power components must be increased, thus increasing Cost, and its life will be shortened. And because the converter IC often needs to control circuits of multiple channels on the same 1C, the user selects an appropriate number of working channels to operate as needed. For the conventional channel current balancing circuit, when the number of working channels changes, the circuit must be changed. How to provide a multi-channel power converter, which simply and effectively distributes the load current evenly to each parallel working channel, has made an important contribution to the multi-channel power converter. The converter of the present invention is composed of a set of main conversion channels and a plurality of parallel conversion channels, wherein the output current of each parallel conversion channel is compared with the output current of the main conversion channel to control the output of each parallel conversion channel Current so that all conversion channels that reach all have the same output current. The overall output voltage is controlled by the error amplifier to achieve the purpose of stable voltage output and balanced current. It can be used not only for single-phase power conversion, but also for multi-phase power conversion. Referring to the second figure, the figure shows a multi-channel pulse width modulation converter with balanced current according to the present invention. The following will be a preferred embodiment of this invention. The paper size of the present invention using four conversion channels is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) (Please read the precautions on the back before filling this page)

565987 A7 _ B7 V. Description of the invention () The converter explains its working principle. The main conversion channel of the converter of the present invention is composed of a pulse width modulator 201, a power switch 205, an inductor 209, an electric current 2 3 1, a motor induction resistance 2 丨 3, and a differential circuit 2 丨 7. The main work is to compare the input signal with a standard two-angle wave to generate a control signal by the pulse width modulator 201 to control the duty cycle of the power switch 205 to form a power output pulse wave, and then pass the inductor 209 and Capacitor 23 丨 is filtered and output to load 232. The differential circuit 217 detects a voltage difference signal on both sides of the current sensing resistor 213, and obtains an output signal VlSEN i ° proportional to the current magnitude. Taking a single parallel conversion channel as an example, it consists of two subtraction circuits 221, 222, The compensation circuit 227, a pulse width modulator 202, a power switch 206, an inductor 210, a capacitor 231, a current sensing resistor 214, and a differential circuit 218 are configured. The difference between the parallel conversion channel and the main conversion channel is that the input signals obtained by the pulse visibility modulators 202 and 201 are different. Except for the input of a standard triangular wave, the input signal on the main conversion channel is the difference signal obtained by comparing the difference between the output average voltage and the reference voltage Vref & by the error amplifier 230 as the input of the pulse width modulator 201 The 彳 ㊁ number 'and the input number of the pulse width modulator 202 in the parallel conversion channel are measured by the current sensing resistor 2 1 4 and the differential circuit 2 1 8 and are proportional to the parallel conversion channel. The difference value obtained by subtracting the current signal Visen2 from the subtraction circuit 222 and V1SEN1, and then providing a proper amplification and chirp through a compensation circuit 227, and sending it to the subtraction circuit 221 and the difference signal output from the error amplifier 230. Minus the signal obtained. Therefore, this paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) (please read the precautions on the back before filling this page) · Printed by the Intellectual Property Bureau Employee Consumer Cooperative of the Ministry of Economic Affairs 565987 A7 B7 V. Invention Description (The two parallel conversion channels in the middle can work without modifying or adding circuits. It provides a simple and effective working circuit for the actual use of the converter of the present invention. Because the main conversion channel does not require a subtraction circuit and a compensation circuit, Therefore, the overall cost is also lower than the conventional converter. The multi-channel pulse width modulation converter with balanced current of the present invention uses a current-sensing resistor and a differential circuit to obtain a ratio proportional to the current of the conversion channel. Compare the signal of the channel with the current signal of the main conversion channel to adjust the PWM duty cycle of the channel so that the current of each channel tends to be the same, but the current sensing resistor does not necessarily need to be an actual series resistance, It can also be obtained when the power switch is turned on, and the current passes through the voltage drop of its on-resistance. Both sides of the resistor obtain the magnitude of the channel current, and the output pulse of the power supply is filtered by the inductor and capacitor to form a DC power supply output, which does not depart from the spirit of the present invention. As understood by those skilled in the art, the above description is only This is only a preferred embodiment of the present invention, and is not intended to limit the scope of patent application of the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention should be included in the scope of patent application described below (Please read the notes on the back before writing this page) Printed on the paper by the Consumers' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, this paper applies the Chinese National Standard (CNS) A4 specification (210X297 mm)

Claims (1)

565987 ABCD 6. Scope of patent application (please read the precautions on the back before filling this page) 1 · A multi-channel pulse width modulation converter with balanced current, the converter contains at least: a power output terminal, which is The power output interface of the converter provides an average output voltage signal; an error amplifier takes a reference voltage signal and the average output voltage signal as inputs, compares the difference between the reference voltage signal and the average output voltage signal, and generates an Converter voltage difference signal output; a main conversion channel connected between the error amplifier and the power output terminal, taking the converter voltage difference signal as input and output-the main channel outputs current to the power output terminal and outputs a main Channel current signal; and the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs prints at least one parallel conversion channel connected between the error amplifier and the power output terminal, and the parallel conversion channel is further connected to the main conversion channel to receive the main channel Current signal, with the main channel current signal and the A difference in current signals of one of the parallel conversion channels generates a first difference signal, and the first difference signal is subtracted from the converter voltage difference signal to generate a second difference signal. The second difference signal is used to adjust the parallel conversion. One of the channels outputs a parallel channel output current, outputs the parallel channel output current to the power output terminal, and measures the parallel channel output current to generate the parallel channel current signal. This paper size applies to China National Standard (CNS) A4 (210X 297 mm) 565987 A8 B8 C8 6. Scope of patent application. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 2. The converter described in item 1 of the scope of patent application, in which the above-mentioned main conversion channel 'further includes: a pulse width modulator. The converter voltage difference signal is input to generate a pulse width modulation signal output; a power switch is connected to the pulse width modulator, and uses the pulse width modulation signal as an input to control the duty cycle of the power switch To generate a pulse wave power output; a wave wave element including an inductor and a capacitor, the filter element connected to the power switch, filtering the pulse wave power source to form the main channel output current; a current sensing resistor, the device is On the output current path of the main conversion channel; and a differential circuit connected to both ends of the current sensing resistor ', taking the voltage across the current sensing resistor as an input to obtain the main circuit which is proportional to the output current of the main circuit Channel current signal. 3. The converter according to item 2 of the scope of patent application, wherein the aforementioned pulse width modulator further comprises a standard triangular wave input. 4. The converter according to item 2 of the scope of patent application, wherein the above-mentioned main conversion channel further includes a kind of on-resistance replaced by one of the power switches] pen_ $ 雨 The current sensing resistor circuit, wherein the differential The circuit is connected to the two ends of the ^ ". ^ Resistor to get the current signal of the main channel and the filter element (please read the precautions on the back before filling in 'write this page)-, τ This paper size is applicable to China Standard (CNS) A4 specification (210X297 Gongchu) 565987 Printed by A8 B8 C8 D8 of the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs VI. Patent application scope After filtering the pulse wave power, the main channel output current is formed and output to the power output end. 5. The converter according to item 1 of the scope of patent application, wherein the parallel conversion channel further includes: a second subtraction circuit that outputs the second difference signal; a pulse width modulator connected to the second The subtraction circuit uses the second difference signal as an input to generate a pulse width modulation signal output. A power switch is connected to the pulse width modulator and uses the pulse width modulation signal as an input to control the power. The duty cycle of the switch generates a pulse wave power output; a chirped wave element including an inductor and a capacitor, the crossing wave element is connected to the power switch, and filters the pulse wave power source to form the parallel channel output current; a current The induction resistance is installed on the output current path of the parallel conversion channel; a differential circuit is connected to both ends of the current induction resistance, and the voltage across the current induction resistance is used as an input to obtain the output current of the parallel channel. Proportional to the current signal of the parallel channel; and a first subtraction circuit connected to the differential circuit and the main conversion channel, The signal and the current signal of the main channel are input, and the difference between the current signal of the parallel channel and the current signal of the main channel is compared, and the first difference signal is output. 15 This paper size applies to China National Standard (CNS) A4 specification (210X 297 mm) ) "(Please read the precautions on the back before filling this page)-* v'tr Box 565987 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs AS B8 C8 D8_______ VI. The scope of the patent application where the second subtraction circuit is based on The _th difference signal and the converter voltage difference signal are inputs, and the first difference signal is output after comparing the differences. 6. The converter according to item 5 of the scope of patent application, wherein the above-mentioned pulse width modulator further includes a standard triangular wave input. 7. The converter according to item 5 of the scope of patent application, wherein the above-mentioned parallel conversion channel further includes a circuit using one of the power switches to replace the current sensing resistor, wherein the differential circuit is connected to the At both ends of the on-resistance, the parallel channel current signal is obtained, and after the filter element is filtered by the pulse wave power supply, the bridging channel output current is formed and more power output terminals are output. 8. The converter according to item 5 of the scope of patent application, wherein the above-mentioned conversion circuit further includes a compensation circuit for providing the function of filtering and filtering, which is located in the first subtraction circuit and the second subtraction circuit. In between, the first difference signal is used as an input to generate a compensated first difference signal, and the second subtraction circuit is output. 9. The converter according to item 1 of the scope of patent application, wherein the above-mentioned reference voltage signal is the voltage requirement of the converter output. This paper size applies to China National Standard (CNS) A4 specifications (210X297 mm) f Please read the notes on the back before filling in this page) # 565987 A8 B8 C8 ____ VI. Patent Application Scope 10 · If the scope of patent application is the first The converter described above, wherein the converter is a single-phase converter. (Please read the precautions on the back before filling this page) 1 1. The converter described in the first paragraph of the scope of patent application, where the above converter is a multi-phase converter. 1 2 · The converter according to item 1 of the scope of patent application, in which the above-mentioned parallel conversion channel has the function of opening or closing according to the needs of use. 1 3. A multi-channel pulse width modulation converter with balanced current, the converter at least includes: a power output terminal, which is the power output interface of the converter, and provides an average output voltage signal; an error The amplifier takes a reference voltage signal and the average output voltage signal as inputs, and compares the difference between the reference voltage signal and the average output voltage signal to generate a converter voltage difference signal output. A main conversion channel is connected to the error amplifier and Between the power output terminals, the main conversion channel includes a printed differential signal printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, and a f & -1ffl > OJ device. The main tone once produces a wide production wave, and the pulse input channel is as follows. To output the main signal, a 1-degree wide wave pulse channel must be turned on. Wave number pulse channel adaptation 7 This paper size is applicable to China National Standard (CNS) A4 specification (21〇X297 public love) 565987 AB CD Into the range, control the duty cycle of the main channel power switch to generate a main channel pulse wave power output, a main channel chirping element, including a main channel inductor and a main channel capacitor, connected to the main channel power switch, The main channel pulse wave power is filtered to form a main conversion channel output current, a main channel current sensing resistor is installed on the output current path of the main conversion channel, and a main channel differential circuit is connected to the main channel current sensing. The two ends of the resistor take the voltage of the two ends of the current sensing resistor of the main channel as an input to obtain a main channel current signal proportional to the output current of the main channel; and at least one parallel conversion channel connected to the error amplifier and the power supply. Between the output terminals, the parallel conversion channel is further connected to the main conversion channel to receive the main channel current signal, and a first difference signal is generated based on a difference between the main channel current signal and a parallel channel current signal of one of the parallel conversion channels. The first difference signal and the conversion The voltage difference signal is subtracted to generate a second difference signal. The second difference signal is used to adjust the parallel channel output current of one of the parallel conversion channels and output to the power output terminal. The output current of the parallel channel is measured to generate the parallel channel. The current signal feeds back the current signal of the parallel channel to the parallel conversion channel, and each of the parallel conversion channels contains the paper standard applicable to the Chinese National Standard (CNS) A4 specification (210X 297 mm) .......... . «(Please read the notes on the back before filling out this page) > vy Printed by the Intellectual Property Bureau Employee Consumer Cooperative of the Ministry of Economic Affairs 565987 A8 B8 C8 D8 6. Apply for a patent scope a second subtraction circuit and output the second difference signal A parallel channel pulse width modulator is connected to the second subtraction circuit. The second difference signal is used as an input to generate / parallel channel pulse width modulation signal output, and a parallel channel power switch is connected to the parallel channel. The pulse width modulator takes the pulse width modulation signal of the parallel channel as an input to control the duty cycle of the power switch of the parallel channel. A parallel channel pulse wave power output, a parallel channel filter element, which is composed of a parallel channel inductor and a parallel channel capacitor, is connected to the parallel channel power switch, and filters the parallel channel pulse wave power to form the parallel channel. Output current, a parallel channel current sensing resistor, installed on the output current path of the parallel conversion channel, a parallel channel differential circuit connected to both ends of the parallel channel current sensing resistor, and two of the parallel channel current sensing resistor The terminal voltage is input to obtain a parallel channel current signal that is proportional to the parallel channel output current. A first subtraction circuit is connected to the parallel channel differential circuit and the main channel differential circuit. The parallel channel current signal and the The main channel current signal is input, and the difference between the parallel channel current signal and the main channel current signal is compared, and the first difference signal is output, and this paper size applies the Chinese National Standard (CNS) A4 specification (210X 297 mm) (please Read the notes on the back before filling out this page)-Order-565987 ABCD Patent application scope f A compensation circuit for providing amplification and filtering functions. The compensation circuit is connected to the first subtraction circuit and takes the first difference signal as an input to generate a compensation signal output. The second subtraction circuit It takes the compensation signal and the converter voltage difference signal as inputs, and outputs the second difference signal after comparing the differences. 14. The converter according to item 13 of the scope of patent application, wherein the above-mentioned reference voltage signal is a voltage requirement output by the converter. 15. The converter according to item 13 of the scope of patent application, wherein the above-mentioned main channel pulse width modulator further includes a standard triangular wave input. 16. The converter according to item 13 of the scope of patent application, wherein the above-mentioned parallel channel pulse width modulator further includes a standard triangular wave input. 17. The converter according to item 13 of the scope of patent application, in which the above-mentioned main method is to be one of the main »Roads The rate-resistance power channel should be synchronizing and flowing η 1 frtio τπ The main 1 should be more obstructive when it comes to subcontracting. 'Telecommunications, communication, and rerouting (please read the precautions on the back before filling out this page)-νά The road should reach the winner, the end color ^ a the master should be connected to the 4 1cu # Xinliu Road Road should be connected to the two, the resistance of the radio wave should be considered, the road should be connected to the main electric output, the main should be connected to the main Wave forming after forming. ^ End source output ^ " The electrical transmission source pulse f / channel should lead to the main output, which will flow 20 paper standards applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 565987 A8 B8 C8 D8 The scope of patent application is 18. The converter according to item 13 of the scope of patent application, wherein the above-mentioned parallel conversion channel further comprises a method of using a parallel channel on-resistance of one of the parallel channel power switches to replace the parallel channel current sensing resistance. Circuit, wherein the parallel channel differential circuit is connected to both ends of the parallel channel on-resistance to obtain the parallel channel current signal and the parallel channel filter element, and the parallel channel pulse wave power is filtered to form the parallel channel output The current is output to the power output. • 19. The converter according to item 13 of the patent application scope, wherein the above converter is a single-phase converter. 20. The converter according to item 13 of the patent application scope, wherein the converter is a multi-phase converter. 2 1. The converter according to item 13 of the scope of patent application, wherein the above-mentioned parallel conversion channel has the function of opening or closing according to the needs of use. (Please read the precautions on the back before filling out this page)-、 Can be printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 21