Isolated AC-DC Converter with Master Controller on Secondary Side and Slave Controller on Primary Side

• US 20110038184A1
• Filed: 06/14/2010
• Published: 02/17/2011
• Est. Priority Date: 08/14/2009
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Zhang, Wanfeng, Krishnamoorthy, Ravishanker, Sutardja, Sehat
• Granted Patent: US 8,374,004 B2
• Time in Patent Office: Days
• US Class Current: 363/21.17
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• CPC Class Codes: H02M 3/33538 of the forward type H02M3/3353, H02M3/33569 take precedence

Abstract

An isolated alternating current (AC)-direct current (DC) converter is disclosed. The isolated AC-DC converter comprises a slave control circuit including a slave driver module configured to receive a command and to control coupling of the slave control circuit to a primary-side inductor of a transformer based on the command, a master control circuit coupled to a secondary-side inductor of the transformer, the master control circuit including a master control module configured to sense a feedback voltage across a load and to generate the command based on the feedback voltage and a reference voltage, and a coupler configured to communicate the command from the master control module to the slave driver module and to provide isolation between the master control module and the slave driver module.

Claims

1. An isolated alternating current (AC)-direct current (DC) converter, comprising:

a slave control circuit that includes;

a slave driver module configured to receive a command and to control coupling of the slave control circuit to a primary-side inductor of a transformer based on the command;

a master control circuit coupled to a secondary-side inductor of the transformer, the master control circuit including a master control module configured to sense a feedback voltage across a load and to generate the command based on the feedback voltage and a reference voltage; and

a coupler configured to communicate the command from the master control module to the slave driver module and to provide isolation between the master control module and the slave driver module.

2. The isolated AC-DC converter of claim 1, wherein the isolated AC-DC converter is configured in a flyback converter topology.

3. The isolated AC-DC converter of claim 2, further comprising:

a diode connected between one end of the secondary-side inductor and the load; and

a capacitor having one end connected between the diode and the load and an opposite end connected to another end of the secondary-side inductor.

4. The isolated AC-DC converter of claim 1, wherein the master control module is configured to transmit at least one of sensed parameters and the command to the load via a non-isolated connection to the load.

5. The isolated AC-DC converter of claim 1, wherein the slave control circuit further includes:

a transistor configured to connect one of between an AC signal source and a rectifier and between the rectifier and the transformer; and

a startup control module configured to control switching of the transistor to selectively provide a supply voltage during startup.

6. The isolated AC-DC converter of claim 2 further comprising:

a switch disposed between the secondary-side inductor and a capacitor;

wherein the switch is controlled by the master control circuit.

7. The isolated AC-DC converter of claim 6, wherein the switch is a high-voltage transistor.

8. The isolated AC-DC converter of claim 6, wherein the master control module is configured to monitor a feedback current and to control the switch based on the feedback current and a reference current.

9. The isolated AC-DC converter of claim 1, wherein the master control module includes a protection circuit that monitors at least one of a temperature of the isolated AC-DC converter, an over-voltage condition, an over-current condition, and a short circuit condition.

10. The isolated AC-DC converter of claim 1, wherein the slave control circuit, the master control circuit and the coupler are implemented on a single integrated circuit.

11. The isolated AC-DC converter of claim 1, wherein the coupler is selected from a group including an optical coupler and a magnetic coupler.

12. The isolated AC-DC converter of claim 1, wherein the master control module is configured to receive at least one of sensed parameters and a control command from the load via a non-isolated connection to the load.

13. The isolated AC-DC converter of claim 1, wherein the isolated AC-DC converter is configured in a forward converter topology.

14. The isolated AC-DC converter of claim 13, further comprising:

a first switch having a first end connected to the secondary-side inductor;

a second switch having a first end connected to a second end of the first switch;

an inductor having a first end connected to the second end of the first switch and a second end connected to the load; and

a capacitor having a first end connected between the inductor and the load.

15. The isolated AC-DC converter of claim 14, wherein the first switch includes a first diode and the second switch includes a second diode.

16. The isolated AC-DC converter of claim 14, wherein the first switch includes a first transistor and the second switch includes a second transistor.

17. The isolated AC-DC converter of claim 16, wherein the first and second transistors are controlled by the master control module.

18. The isolated AC-DC converter of claim 16, wherein the first transistor is a high-voltage transistor and the second transistor is a low-voltage transistor.

19. The isolated AC-DC converter of claim 13, further comprising:

a first switch having a first end connected to the secondary-side inductor;

a second switch having a first end connected to a second end of the first switch;

an inductor having a first end connected to a second end of the second switch and a second end connected to the load; and

a capacitor having a first end connected between the inductor and the load.

20. The isolated AC-DC converter of claim 19 wherein the first switch and the second switch are low-voltage transistors controllable by the master control module.