Flyback converter

Patent metadata

Field	Value
Publication number	US-9954456-B2
Application number	US-201715700067-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Sep 9, 2016
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A converter circuit is disclosed. The converter circuit includes a transformer and a primary circuit connected to the primary side of the transformer, where the primary circuit includes a first switch connected to a ground. The converter circuit also includes a second switch connected to the first switch, and a clamping capacitor connected to the second switch and to the input. The converter circuit also includes a secondary circuit connected to the secondary side of the transformer, where the secondary circuit includes a rectifying element, and an output capacitor connected to the rectifying element. In addition, the output capacitor has a substantial effect on resonance of the converter circuit.

First claim

What is claimed is:

1. A converter circuit, comprising:
an input;
a transformer having a primary side and a secondary side;
a primary circuit connected to the primary side of the transformer, wherein the primary circuit comprises:
a first switch connected to a ground,
a second switch connected to the first switch, and
a clamping capacitor connected to the second switch and to the input;

a secondary circuit connected to the secondary side of the transformer, wherein the secondary circuit comprises:
a rectifying element, and
an output capacitor connected to the rectifying element,

wherein a capacitance ratio defined by the value of the capacitance of the output capacitor divided by the square of the turns ratio of the transformer divided by the value of the capacitance of the clamping capacitor is less than 40.

2. The converter circuit of claim 1 , wherein the rectifying element comprises a diode.

3. The converter circuit of claim 1 , wherein the rectifying element comprises a rectifying switch.

4. The converter circuit of claim 1 , wherein the clamping capacitor has a substantial effect on resonance of the circuit.

5. The converter circuit of claim 1 , wherein the clamping capacitor has substantially no effect on resonance of the circuit.

6. The converter circuit of claim 1 , wherein the secondary circuit further comprises:
a second rectifying element, and
a second output capacitor connected to the second rectifying element,
wherein resonance of the converter circuit is affected by the second output capacitor.

7. The converter circuit of claim 1 , wherein the output capacitor is connected directly to a load.

8. The converter circuit of claim 1 , wherein the secondary circuit further comprises an LC filter connected to the output capacitor, wherein the LC filter is configured to generate a voltage output having less ripple than a ripple across the output capacitor.

Assignees

• Navitas Semiconductor Inc

Inventors

• Xue Lingxiao
• Zhang Ju

Classifications

• H02M1/44

  Circuits or arrangements for compensating for electromagnetic interference in converters or inverters · CPC title

• H02M3/33592 Primary

  having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer · CPC title

• H02M1/083

  for the ignition at the zero crossing of the voltage or the current · CPC title

• H02M2001/0058

  Electricity · mapped topic

• H02M3/33569

  having several active switching elements (H02M3/3353 takes precedence) · CPC title