Power converter with a wave generator that filters a wave signal to generate an output voltage

Patent metadata

Field	Value
Publication number	US-9559583-B2
Application number	US-201414153405-A
Country	US
Kind code	B2
Filing date	Jan 13, 2014
Priority date	Jan 13, 2014
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A power converter includes a wave generator, a low pass filter, a first control circuit, and a second control circuit. The wave generator receives an input voltage, and converts the input signal into a wave signal according to a first control signal and a second control signal. The low pass filter filters the wave signal to generate an output voltage. The first control circuit generates the first control signal according to the wave signal and the output voltage. The second control circuit generates the second control signal according to the wave signal and the output voltage.

First claim

What is claimed is:

1. A power converter, comprising:
a wave generator, receiving an input voltage, and converting the input signal into a wave signal according to a first control signal and a second control signal;
a low pass filter, filtering the wave signal to generate an output voltage;
a first control circuit, receiving the wave signal directly from the wave generator, the first control circuit generating the first control signal according to the wave signal and the output voltage; and
a second control circuit, receiving the wave signal directly from the wave generator, the second control circuit generating the second control signal according to the wave signal and the output voltage;
wherein the first control circuit comprises a first comparator and a first capacitor, the wave signal controls a charging operation of the first capacitor, and the comparator generates the first control signal according to a voltage of the first capacitor and the output voltage and a predetermined voltage difference;
wherein the first control circuit further comprises: a first current source, outputting a first current for charging or discharging the first capacitor;
wherein the first current is proportional to a difference between the input voltage and the output voltage;
wherein the second control circuit comprises a second comparator and a second capacitor, the wave signal controls a charging operation of the second capacitor, and the second comparator generates the second control signal according to a voltage of the second capacitor, the output voltage and a predetermined voltage difference.

2. The power converter as claimed in claim 1 , wherein the wave generator comprises:
a driver, generating a driving signal according to the first control signal and the second control signal;
a first PMOS transistor (P-channel Metal-Oxide-Semiconductor Field-Effect Transistor), wherein the first PMOS transistor has a gate for receiving the driving signal, a source coupled to the input voltage, and a drain coupled to a switch node; and
a first NMOS transistor (N-channel Metal-Oxide-Semiconductor Field-Effect Transistor), wherein the first NMOS transistor has a gate for receiving the driving signal, a source coupled to a ground voltage, and a drain coupled to the switch node, wherein the switch node is used to output the wave signal.

3. The power converter as claimed in claim 1 , wherein the first control circuit generates the first control signal to control falling edges of the wave signal, and the second control circuit generates the second control signal to control rising edges of the wave signal.

4. The power converter as claimed in claim 1 , wherein the first control circuit further comprises:
a second current source, outputting a second current, where the first current source is coupled to a first input terminal of the first comparator and the second current source is coupled to a second input terminal of the first comparator.

5. The power converter as claimed in claim 4 , wherein the second current is proportional to a difference between the input voltage and the output voltage.

6. The power converter as claimed in claim 1 , wherein the first control circuit further comprises:
a first transistor, coupled to a first input terminal of the first comparator; and
a second transistor, coupled to a second input terminal of the first comparator.

7. The power converter as claimed in claim 1 , wherein the wave signal controls an open/closed status of a switch coupled in parallel to the first capacitor so as to control the charging operation of the first capacitor.

8. The power converter as claimed in claim 1 , wherein the second control circuit further comprises:
a first current source, outputting a first current to charge or discharge the second capacitor.

9. The power converter as claimed in claim 8 , wherein the first current is proportional to the output voltage.

10. The power converter as claimed in claim 8 , wherein the second control circuit further comprises:
a second current source, outputting a second current, where the first current source is coupled to a first input terminal of the second comparator and the second current source is coupled to a second input terminal of the second comparator.

11. The power converter as claimed in claim 10 , wherein the second current is proportional to the output voltage.

12. The power converter as claimed in claim 1 , wherein the second control circuit further comprises:
a first transistor, coupled to a first input terminal of the second comparator; and
a second transistor, coupled to a second input terminal of the second comparator.

13. The power converter as claimed in claim 1 , wherein the wave signal controls an open/closed status of a switch coupled in parallel to the second capacitor so as to control the charging operation of the second capacitor.

Assignees

• Mediatek Inc

Inventors

• Lin Hung-Chih
• Wang Hung-I
• Hong Hao-Ping
• Kuan Chien-Wei
• Yen Yung-Chih

Classifications

• H02M3/1563

  without using an external clock (H02M3/158 takes precedence) · CPC title

• H02M3/156 Primary

  with automatic control of output voltage or current, e.g. switching regulators · CPC title