Synchronous rectification for DC-DC converters

Patent metadata

Field	Value
Publication number	US-12500523-B2
Application number	US-202318391234-A
Country	US
Kind code	B2
Filing date	Dec 20, 2023
Priority date	Dec 20, 2023
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

The disclosure provides a method for enabling synchronous rectification in a converter, such as, but not limited to a CLLLC circuit. The converter includes a primary side circuit, a transformer, and a secondary side circuit. The method includes receiving a signal indicative of a current from the transformer to the secondary side circuit and measuring a duty cycle of the signal. The duty cycle includes a first pulse width being above a reference voltage and a second pulse width being below the reference voltage. The method also includes determining a difference between the first pulse width and the second pulse width and adjusting the reference voltage based on the determined difference.

First claim

What is claimed is:

1 . A method for enabling synchronous rectification in a converter, the converter having a primary side circuit, a transformer, and a secondary side circuit, the method comprising:
receiving a signal indicative of a current from the transformer to the secondary side circuit; measuring a duty cycle of the signal, the duty cycle comprising a first pulse width being above a reference voltage and a second pulse width being below the reference voltage; determining a difference between the first pulse width and the second pulse width; and adjusting the reference voltage based on the determined difference.

2 . The method of claim 1 , wherein when the difference is a positive value, increasing the reference voltage.

3 . The method of claim 1 , wherein when the difference is a negative value, decreasing the reference voltage.

4 . The method of claim 1 , further comprising:
adjusting the reference voltage based on the determined difference when the difference is greater than a threshold value.

5 . The method of claim 1 , wherein the converter comprises a CLLLC (Capacitor-Inductor-Inductor-Inductor-Capacitor) circuit.

6 . The method of claim 1 , wherein the signal indicative of the current is sensed by a current sensor, the current sensor being a Hall effect sensor.

7 . A controller for enabling synchronous rectification in a converter, the converter having a primary side circuit, a transformer, and a secondary side circuit, the controller positioned on the primary side circuit, the controller comprising:
a comparator unit receiving a signal from a current sensor positioned between the transformer and the secondary side circuit; a PWM module receiving an analog signal from the comparator unit and outputting a digital signal indicative of a duty cycle of the received analog signal, the duty cycle comprising a first pulse width being above a reference voltage and a second pulse width being below the reference voltage; a PWM comparator comparing the first pulse width and the second pulse width and outputting a comparison value; and a voltage adjust module adjusting the reference voltage based on the comparison value.

8 . The controller of claim 7 , wherein when the comparison value is a positive value, the voltage adjust module increases the reference voltage.

9 . The controller of claim 7 , wherein when the comparison value is a negative value, the voltage adjust module decreases the reference voltage.

10 . The controller of claim 7 , wherein the voltage adjust module adjusts the reference voltage when the comparison value is greater than a threshold value.

11 . The controller of claim 7 , wherein the converter comprises a CLLLC (Capacitor-Inductor-Inductor-Inductor-Capacitor) circuit.

12 . The controller of claim 7 , wherein the current sensor is a Hall effect sensor.

Assignees

• Vitesco Technologies Usa Llc

Inventors

• Hanson Justin M

Classifications

• H02M3/33573

  Full-bridge at primary side of an isolation transformer · CPC title

• H02M1/0025

  Arrangements for modifying reference values, feedback values or error values in the control loop of a converter · CPC title

• H02M3/01

  Resonant DC/DC converters · CPC title

• H02M3/33584

  Bidirectional converters · 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