Converter circuit and method with auxiliary supply voltage

• US 20020114172A1
• Filed: 02/21/2002
• Published: 08/22/2002
• Est. Priority Date: 02/19/2001
• Status: Active Grant

• Current Assignee: Flextronics International USA Incorporated (Flex, Ltd.)
• Original Assignee: Rockwell Scientific Company, LLC (Teledyne Technologies Incorporated)
• Inventors: Webb, Kenneth F., Sun, Jian
• Granted Patent: US 6,775,159 B2
• Time in Patent Office: Days
• US Class Current: 363/16
• CPC Class Codes: B41J 2/465 using masks, e.g. light-switching masks
• CPC Class Codes: B41J 2/471 using dot sequential main scanning by means of a light deflector, e.g. a rotating polygonal mirror
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: H02M 7/064 with several outputs
• CPC Class Codes: Y02P 70/10 Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Abstract

A converter circuit comprises a magnetic core, a primary winding, a secondary winding, a main rectification circuit, an auxiliary rectification circuit. The primary winding and the secondary winding are wound around the magnetic core. The main rectification circuit and the auxiliary rectification circuit are both connected to the secondary winding and produce output voltages having different magnitudes. The auxiliary voltage powers the control and drive circuits for both the primary switches and the synchronous rectifiers used for the main rectification circuit.

Claims

1. A converter circuit comprising:

a transformer core;

a primary winding, the primary winding being wound around the transformer core;

a secondary winding, the secondary winding being wound around the transformer core;

a main rectification circuit;

an auxiliary rectification circuit;

wherein the main rectification circuit and the auxiliary rectification circuit are both connected to the secondary winding and produce output voltages having different magnitudes.

2. A circuit according to claim 1, further comprising

a drive circuit, the drive circuit being coupled to receive a supply voltage;

a drive control circuit, the drive control circuit being coupled to the drive circuit and controlling the drive circuit to apply a pulse width modulated voltage to

the primary winding;

wherein the main rectification circuit comprises a first output capacitor and a rectifier that controls current flow through the first output capacitor; and

wherein the drive control circuit synchronizes operation of the rectifier to the pulse width modulated voltage.

3. A circuit according to claim 2,

wherein the output voltage produced by the auxiliary rectification circuit is provided to the drive control circuit;

and

wherein the drive control circuit uses the output voltage produced by the auxiliary rectification circuit to produce a control signal for the rectifier, a magnitude of the voltage of the control signal being determined at least in part by the magnitude of the output voltage of the auxiliary rectification circuit.

4. A circuit according to claim 3, wherein the magnitude of the output voltage produced by the auxiliary rectification circuit is approximately two times the magnitude of the output voltage produced by the main rectification circuit.

5. A circuit according to claim 3, wherein the magnitude of the output voltage produced by the auxiliary rectification circuit is approximately four times the magnitude of the output voltage produced by the main rectification circuit.

6. A circuit according to claim 3, wherein the output capacitor produces a DC output voltage that is less than about ten volts and produces a DC output current that is more than about ten amps.

7. A circuit according to claim 3, wherein the output capacitor produces a DC output voltage that is less than about five volts and produces a DC output current that is more than about thirty amps.

8. A circuit according to claim 1,

wherein the main rectification circuit comprises a first output capacitor and the auxiliary rectification circuit comprises a second output capacitor;

and

wherein the output voltage of the main rectification circuit is produced across the first output capacitor and the output voltage of the auxiliary rectification circuit is produced across the second output capacitor.

9. A circuit according to claim 8, wherein a terminal of the first output capacitor is directly connected to a terminal of the second output capacitor.

10. A circuit according to claim 8, further comprising a rectifier, wherein a first current passes through the first output capacitor and the rectifier, and wherein a second current passes through the second output capacitor and the rectifier.

11. A circuit according to claim 8, wherein the output voltage of the main rectification circuit is in a range of about zero to four volts and the output voltage of the auxiliary rectification circuit is in a range of about five to twenty volts.

12. A circuit according to claim 8, wherein the output voltage of the main rectification circuit is about three volts and the output voltage of the auxiliary rectification circuit is about six to twelve volts.

14. A method according to claim 13, further comprising

controlling a flow of the first component of the secondary current with a rectifier;

controlling operation of the rectifier with a drive control circuit, the drive control circuit being connected to the second capacitor, the drive control circuit using the second output voltage to produce a control signal for the rectifier, a magnitude of the voltage of the control signal being determined at least in part by the magnitude of the second output voltage.

15. A method according to claim 14,

wherein the primary current is provided to the primary winding using a drive circuit that applies a pulse width modulated voltage to the primary winding;

wherein the method further comprises controlling the drive circuit with a drive control circuit, the drive control circuit controlling the drive circuit and the rectifier so that operation of the rectifier is synchronized to the operation of the drive circuit.

17. A circuit according to claim 16,

wherein the main rectification circuit comprises an inductor, a first rectifier, a second rectifier, and a first output capacitor;

wherein the auxiliary rectification circuit comprises a third rectifier and a second output capacitor;

wherein the inductor is coupled between a first terminal of the secondary winding and a first terminal of the first output capacitor;

wherein the first rectifier is coupled between a second terminal of the secondary winding and a second terminal of the first output capacitor;

wherein the second rectifier is coupled between the first terminal of the secondary winding and the second terminal of the output capacitor;

wherein a first terminal of the second output capacitor is coupled to the second terminal of the first output capacitor; and

wherein the third rectifier is coupled between the first terminal of the secondary winding and a second terminal of the second output capacitor.

18. A circuit according to claim 16,

wherein the main rectification circuit comprises an inductor, a first rectifier, a second rectifier, and a first output capacitor;

wherein the auxiliary rectification circuit comprises a third rectifier and a second output capacitor;

wherein, in operation, a first current flows from the secondary winding and through the inductor, the first output capacitor, and the first rectifier to charge the first output capacitor; and

wherein, in operation, a second current flows from the secondary winding and through the third rectifier, the second output capacitor and the second rectifier to charge the second output capacitor.

19. A circuit according to claim 16

wherein the main rectification circuit comprises a first inductor, a second inductor, a first rectifier, a second rectifier, and a first output capacitor;

wherein the auxiliary rectification circuit comprises a third rectifier, a fourth rectifier, and a second output capacitor;

wherein the first rectifier and the second rectifier are connected end to end between first and second terminals of the secondary winding;

wherein the third rectifier and the fourth rectifier are connected end to end between the first and second terminals of the secondary winding; and

wherein the first output capacitor is connected between (a) a junction of the first inductor and the second inductor and (b) a junction of the first rectifier and the second rectifier;

wherein the second output capacitor is connected between (a) the junction of the first rectifier and the second rectifier and (b) a junction of the third rectifier and the fourth rectifier.

20. A circuit according to claim 19, wherein the first inductor and the second inductor are each implemented using an integrated magnetic winding structure that is shared with the secondary winding.

21. A circuit according to claim 16,

wherein the main rectification circuit comprises a first inductor, a second inductor, a first rectifier, a second rectifier, and a first output capacitor;

wherein the auxiliary rectification circuit comprises a third rectifier, a fourth rectifier, and a second output capacitor;

wherein, in operation, a first current flows through the first inductor, the first output capacitor, and the second rectifier to charge the first output capacitor when a voltage of a first polarity is applied to the primary winding;

wherein, in operation, a second current flows through the third rectifier, the second output capacitor and the second rectifier to charge the second output capacitor when the voltage of the first polarity is applied to the primary winding;

wherein, in operation, a third current flows through the second inductor, the first output capacitor, and the first rectifier when a voltage of a second polarity is applied to the primary winding, the second polarity being opposite the first polarity; and

wherein, in operation, a fourth current flows through the fourth rectifier, the second output capacitor, and the first rectifier when the voltage of the second polarity is applied to the primary winding.

22. A circuit according to claim 16,

wherein the main rectification circuit comprises a first rectifier, a second rectifier, an inductor, and a first output capacitor;

wherein the auxiliary rectification circuit comprises a third rectifier, a fourth rectifier, and a second output capacitor;

wherein the first rectifier is connected between a first terminal of the secondary winding and a first terminal of the first output capacitor;

wherein the second rectifier is connected between a second terminal of the secondary winding and a first terminal of the second output capacitor;

wherein the third rectifier is connected between the first terminal of the secondary winding and a second terminal of the second output capacitor;

wherein the fourth rectifier is connected between the second terminal of the secondary winding and the second terminal of the second output capacitor; and

wherein the inductor is connected between a third terminal of the secondary winding and a second terminal of the first output capacitor.

23. A circuit according to claim 16,

wherein the main rectification circuit comprises a first rectifier, a second rectifier, and a first output capacitor;

wherein the auxiliary rectification circuit comprises a third rectifier, a fourth rectifier, and a second output capacitor;

wherein, in operation, a first current flows from the secondary winding, through the inductor, the first output capacitor, and the first rectifier to charge the first output capacitor when a voltage of a first polarity is applied to the primary winding;

wherein, in operation, a second current flows from the secondary winding, through the fourth rectifier, the second output capacitor, and the first rectifier to charge the second output capacitor when the voltage of the first polarity is applied to the primary winding;

wherein, in operation, a third current flows from the secondary winding, through the inductor, the first output capacitor and the second rectifier to charge the first output capacitor when a voltage of a second polarity is applied to the primary winding, the second polarity being opposite the first polarity; and

wherein, in operation, a fourth current flows from the secondary winding, through the third rectifier, the second output capacitor, and the second rectifier to charge the second output capacitor when the voltage of the second polarity is applied to the primary winding.

24. A circuit according to claim 16,

wherein the main rectification circuit comprises a first rectifier and a first output capacitor;

wherein the auxiliary rectification circuit comprises a second rectifier and a second output capacitor;

wherein the first output capacitor and the first rectifier are connected end to end across the secondary winding; and

wherein the second output capacitor and the second rectifier are connected end to end between (a) a junction of the first output capacitor and the first rectifier and (b) a junction of the secondary winding and the first rectifier.

25. A circuit according to claim 16,

wherein the main rectification circuit comprises a first rectifier and a first output capacitor;

wherein the auxiliary rectification circuit comprises a second rectifier and a second output capacitor;

wherein a first terminal of the first output capacitor is coupled to a first terminal of the secondary winding;

wherein a first terminal of the first rectifier and a first terminal of the second rectifier are coupled to a second terminal of the secondary winding;

wherein a second terminal of the first output capacitor and a second terminal of the first rectifier are coupled to a first terminal of the second output capacitor; and

wherein a second terminal of the second output capacitor is coupled to a second terminal of the second rectifier.

26. A circuit according to claim 16,

wherein the main rectification circuit comprises a first rectifier and a first output capacitor;

wherein the auxiliary rectification circuit comprises a second rectifier and a second output capacitor;

wherein, in operation, a first current flows from the secondary winding and through the first output capacitor to charge the first output capacitor when a zero voltage is applied to the primary winding;

wherein, in operation, a second current flows from the secondary winding and through the second rectifier, the second output capacitor, and the first output capacitor to charge the second output capacitor when a non-zero voltage is applied to the primary winding; and

wherein, in operation, after the second output capacitor charges when the non-zero voltage is applied, additional energy is stored in the transformer core and the additional stored energy is used to produce the first current when the zero voltage is applied to the primary winding.

13. A method comprising:

providing a primary current to a primary winding of a dc/dc converter, the primary winding being wound around a transformer core;

producing a secondary current in a secondary winding in response to the primary current, the secondary winding being wound around the transformer core and being magnetically coupled to the primary winding;

splitting the secondary current between first and second circuit branches to produce first and second components of the secondary current, the first circuit branch comprising a first output capacitor and the second current branch comprising a second output capacitor;

charging the first output capacitor to a first output voltage with the first component of the secondary current; and

charging the second output capacitor to a second output voltage with the second component of the secondary current, the second output voltage being different than the first output voltage.

16. A dc/dc converter circuit comprising:

a transformer core;

a primary winding, the primary winding being wound around the transformer core;

a secondary winding, the secondary winding being wound around the transformer core;

a main rectification circuit, the main rectification circuit being connected to the secondary winding, the main rectification circuit further comprising a first output capacitor and a rectifier that controls current flow through the first output capacitor, and an output voltage of the main rectification circuit being produced across the first output capacitor;

an auxiliary rectification circuit, the auxiliary rectification circuit being connected to the secondary winding, the auxiliary rectification circuit further comprising a second output capacitor, and an output voltage of the auxiliary rectification circuit being produced across the second output capacitor, the output voltage of the auxiliary rectification circuit having a magnitude which is different than a magnitude of the output voltage of the main rectification circuit;

a drive circuit, the drive circuit being coupled to receive a supply voltage; and

a drive control circuit, the drive control circuit being coupled to the drive circuit and controlling the drive circuit to apply a pulse width modulated dc voltage to the primary winding, the drive control circuit controlling the rectifier to synchronize operation of the rectifier to the pulse width modulated voltage, the drive control circuit being connected to receive the output voltage produced by the auxiliary rectification circuit, the drive control circuit being powered by the output voltage produced by the auxiliary rectification circuit to produce a control signal for the drive circuit, the control signal producing a pulse with duration determined at least in part by the magnitude of the output voltage of the main rectification circuit.