Voltage conversion circuit and method, and multiphase parallel power system

Patent metadata

Field	Value
Publication number	US-10164536-B2
Application number	US-201815902782-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Aug 25, 2015
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A voltage conversion circuit and method, and a multiphase parallel power system, where in the voltage conversion circuit, a feedback circuit provides a frequency-controllable feedback ripple signal. Therefore, the voltage conversion circuit has a controllable operating frequency, and a frequency requirement of a load may be met. Compensation does not need to be performed in a hysteresis mode, and therefore the hysteresis mode has a fast-speed response. The operating frequency is fixed. Therefore, the voltage conversion circuit in the embodiments may be applied to the multiphase parallel power system such that the multiphase parallel power system is applicable to an application scenario with a large load current.

First claim

What is claimed is:

1. A voltage conversion circuit, comprising:
a voltage conversion subcircuit comprising a power transistor, a first energy storage element coupled to the power transistor, and a second energy storage element coupled to the power transistor and the first energy storage element, and wherein the voltage conversion subcircuit is configured to control conduction or cutoff of the power transistor to control the first energy storage element and the second energy storage element to receive and store energy of a first direct current voltage in order to output a second direct current voltage at a coupling end of the first energy storage element and the second energy storage element; and
a feedback loop, comprising:
a sampling and amplification circuit;
a feedback circuit; and
a comparator circuit coupled to the sampling and amplification circuit and the feedback circuit,
wherein the sampling and amplification circuit is coupled to the coupling end and is configured to:
sample the second direct current voltage to obtain a sampling signal; and
input the sampling signal to the comparator circuit,

wherein the feedback circuit is coupled to the coupling end and is configured to:
sample the second direct current voltage to obtain a sample second direct current voltage;
combine the sampled second direct current voltage and a frequency-controllable triangular wave signal into a frequency-controllable feedback ripple signal; and
input the frequency-controllable feedback ripple signal to the comparator circuit,

wherein the comparator circuit is configured to:
compare the sampling signal with the frequency-controllable feedback ripple signal; and
output a frequency-controllable pulse width modulated (PWM) signal,

wherein the frequency-controllable PWM signal controls the conduction or the cutoff of the power transistor, and
wherein a frequency of the frequency-controllable PWM signal is the same as a frequency of the frequency-controllable feedback ripple signal.

2. The voltage conversion circuit according to claim 1 , wherein the feedback circuit comprises a triangular wave signal generator, a frequency control subcircuit coupled to the triangular wave signal generator, and a direct current control subcircuit coupled to the frequency control subcircuit, wherein the triangular wave signal generator is configured to generate the frequency-controllable triangular wave signal, wherein the frequency control subcircuit is configured to enable the frequency of the frequency-controllable feedback ripple signal to be the same as a frequency of the frequency-controllable triangular wave signal, and wherein the direct current control subcircuit is configured to control a direct current component voltage of the frequency-controllable feedback ripple signal according to the second direct current voltage and a direct current component of the frequency-controllable triangular wave signal.

3. The voltage conversion circuit according to claim 2 , wherein the frequency control subcircuit comprises a first capacitor and a second capacitor, wherein the direct current control subcircuit comprises a first resistor and a second resistor, wherein the triangular wave signal generator is coupled to the comparator circuit using the first capacitor, wherein the second capacitor is coupled between the comparator circuit and the coupling end of the first energy storage element and the second energy storage element, wherein the first resistor is coupled between the comparator circuit and the coupling end of the first energy storage element and the second energy storage element, and wherein the second resistor is coupled between the comparator circuit and a ground terminal.

4. The voltage conversion circuit according to claim 1 , wherein the sampling and amplification circuit comprises a bleeder sampling circuit and an error amplification circuit coupled to the bleeder sampling circuit, and wherein the bleeder sampling circuit is configured to:
perform bleeder sampling on the second direct current voltage to obtain a bleeder sampling signal; and
input the bleeder sampling signal to the error amplification circuit, and
wherein the error amplification circuit is configured to:
compare the bleeder sampling signal with a preset reference voltage signal;
amplify a difference signal of the bleeder sampling signal and the preset reference voltage signal to obtain the sampling signal; and
input the sampling signal to the comparator circuit.

5. The voltage conversion circuit according to claim 4 , wherein the bleeder sampling circuit comprises a third resistor and a fourth resistor, wherein the third resistor is coupled between the error amplification circuit and the coupling end of the first energy storage element and the second energy storage element, and wherein the fourth resistor is coupled between the error amplification circuit and a ground terminal.

6. The voltage conversion circuit according to claim 1 , wherein the feedback loop further comprises a logic circuit and a drive circuit, wherein an output end of the comparator circuit is coupled to the power transistor by successively using the logic circuit and the drive circuit, wherein the logic circuit is configured to compare the frequency-controllable PWM signal with a preset control logic signal to obtain a control signal using which the conduction and the cutoff of the power transistor are controlled, and wherein the drive circuit is configured to:
convert the control signal into a drive signal that has a current driving capability; and
set the drive signal to control the conduction and the cutoff of the power transistor.

7. The voltage conversion circuit according to claim 1 , wherein the power transistor comprises a first power transistor and a second power transistor, wherein the second power transistor is cut off when the first power transistor is conducted, wherein the second power transistor is conducted when the first power transistor is cut off, wherein the first energy storage element and the second energy storage element are coupled to the first power transistor and the second power transistor, wherein the first direct current voltage is configured to charge the second energy storage element through the first energy storage element when the first power transistor is conducted and the second power transistor is cut off, and wherein the second energy storage element is configured to discharge through the first energy storage element using the second power transistor when the first power transistor is cut off and the second power transistor is conducted.

8. The voltage conversion circuit according to claim 1 , wherein the power transistor comprises a first power transistor and a second power transistor, wherein the second power transistor is cut off when the first power transistor is conducted, wherein the second power transistor is conducted when the first power transistor is cut off, wherein the first energy storage element and the second energy storage element are coupled to the first power transistor and the second power transistor, wherein when the first power transistor is conducted and the second power transistor is cut off, the first direct current voltage is configured to store energy using the first energy storage element, and the second energy storage element is configured to discharge, and wherein when the first power transistor is cut off and the second power transistor is conducted, the first energy storage element is configured to release energy using the second power transistor, and the first energy storage element and the first direct current voltage are configured to charge the second energy storage element.

9. The voltage conversion circuit according to claim 1 , w

Assignees

• Huawei Tech Co Ltd

Inventors

• Huang Chen

Classifications

• H03K7/08

  Duration or width modulation {; Duty cycle modulation} · CPC title

• H02M1/08

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title

• H02M3/1582 Primary

  Buck-boost converters (H02M3/1584 takes precedence) · CPC title

• H03K5/04

  by increasing duration; by decreasing duration · CPC title

• H03K4/06

  having triangular shape · CPC title