Isolated AC-DC converter with master controller on secondary side and slave controller on primary side

• US 8,374,004 B2
• Filed: 06/14/2010
• Issued: 02/12/2013
• 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: Sutardja, Sehat, Krishnamoorthy, Ravishanker, Zhang, Wanfeng
• Primary Examiner(s): Vu, Bao Q
• Application Number:
  US12/814,957
• Publication Number:
  US 20110038184A1
• Time in Patent Office: 974 Days
• Field of Search: 363/21.12, 363/21.15, 363/21.16, 363/21.17, 363/97, 363/131
• US Class Current: 363/21.12
• 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 first transistor configured to connect to a primary side inductor of a transformer; and

a slave driver module configured to, based on receiving a command, control switching of the first transistor;

a master control circuit that includes;

a first diode having an input connected to a first end of a secondary side inductor of the transformer;

a capacitor having a first end and a second end, wherein the first end of the capacitor is connected to (i) an output of the first diode and (ii) a load, and wherein the second end of the capacitor is connected to a second end of the secondary side inductor; and

a master control module configured to sense a feedback voltage across the load, and generate the command based on (i) the feedback voltage and (ii) a reference voltage; and

a coupler configured to communicate the command from the master control module to the slave driver module, and 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 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.

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

a second 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 second transistor to selectively provide a supply voltage during startup.

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

6. The isolated AC-DC converter of claim 5, further comprising:

a second diode having an output connected to the output of the first diode; and

an inductor having a first end and a second end, wherein the first end of the inductor is connected to the output of the first diode, and wherein the second end of the inductor is connected to the load.

7. The isolated AC-DC converter of claim 1, wherein the first transistor is an ultra high voltage (UHV) transistor.

8. 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.

9. The isolated AC-DC converter of claim 1, wherein the master control module is configured to monitor a feedback current.

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. A method of operating an isolated alternating current (AC)-direct current (DC) converter, the method comprising:

receiving a command at a slave driver module of a slave control circuit, wherein a first transistor of the slave control circuit is connected to a primary side inductor of a transformer;

controlling switching of the first transistor based on the slave driver module receiving the command;

providing a first diode of a master control circuit, the first diode having an input connected to a first end of a secondary side inductor of the transformer;

providing a capacitor having a first end connected to (i) an output of the first diode and (ii) a load, and a second end connected to a second end of the secondary side inductor; and

sensing a feedback voltage across the load,

wherein the command received by the slave driver module is generated based on (i) the feedback voltage and (ii) a reference voltage.

14. The method of claim 13, further comprising transmitting at least one of sensed parameters and the command to the load via a non-isolated connection to the load.

15. The method of claim 13, further comprising:

controlling switching of a second transistor of the slave control circuit to selectively provide a supply voltage during startup, wherein the second transistor is connected one of between an AC signal source and a rectifier and between the rectifier and the transformer.

16. The method of claim 13, further comprising monitoring at least one of 6 temperature of the isolated AC-DC converter, an over-voltage condition, an over-current condition, and a short circuit condition.

17. The method of claim 13, further comprising:

monitoring a feedback current.

18. The method of claim 13, further comprising receiving at least one of sensed parameters and a control command from the load via a non-isolated connection to the load.