Buck converter with demagnetization detection of the inductor

• US 7,495,425 B2
• Filed: 01/17/2006
• Issued: 02/24/2009
• Est. Priority Date: 01/18/2005
• Status: Expired due to Fees

• Current Assignee: Puls GmbH
• Original Assignee: Puls GmbH
• Inventors: Friedrich, Heiner
• Primary Examiner(s): Ullah; Akm E
• Assistant Examiner(s): BEHM, HARRY RAYMOND
• Application Number:
  US11/332,486
• Publication Number:
  US 20060158160A1
• Time in Patent Office: 1,134 Days
• Field of Search: 323/290, 323/285, 323/282, 323/284, 323/247, 323/259
• US Class Current: 323/290
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A buck converter is equipped with a switch, a diode, an inductance, a capacitor, an input with a first connection and second connection, and an output with a first connection and second connection. The first connection of the input is connected to the first connection of the output via a series circuit comprised of the switch and the inductance; in particular, the switch is provided on the input side and the inductance is provided on the output side. In addition, the cathode of the diode is connected to the connection between the switch and the inductance while the anode of the diode is connected to the second connection of the input and to the second connection of the output. The capacitor is connected in parallel with the connections of the output. It is possible to trigger the switch by combining a first signal with a second signal and a third signal corresponding to a control variable from the output of the buck converter may be used to adjust the output signal.

Claims

1. A buck converter comprising:

an input with a first connection (101) and second connection (102),

an output with a first connection (103) and second connection (104),

a switch (110),

a diode (D1) having a cathode and an anode

an inductance (L1),

a capacitor (C1),

wherein the first connection (101) of the input is connected to the first connection (103) of the output via a series circuit comprised of the switch (110) and the inductance (L1), the cathode of the diode (D1) is connected to the connection between the switch (110) and the inductance (L1), the anode of the diode (D1) is connected to the second connection (102) of the input and to the second connection (104) of the output, and the capacitor (C1) is connected in parallel with the connections (103, 104) of the output, such that the switch (110) is triggered from a first state to a second state by combining a first signal with a second signal,

wherein the switch is triggered by combining the first signal with the second signal and a third signal,

wherein the second signal is an essentially triangular shaped signal generated by a saw tooth generator, and

means for adding the current signal and the essentially triangular shaped signal by integration of a voltage in the inductance (L1) and an additional voltage.

2. The buck converter as recited in claim 1, wherein the first connection (101) of the input is of a positive polarity and the second connection (102) of the input is of a negative polarity.

3. The buck converter as recited in claim 1, wherein the third signal is a control variable from the output of the buck converter and is used to adjust the output signal of the buck converter and is substantially constant.

4. The buck converter as recited in claim 1, further including means for regulating, wherein the third signal is adjustable or controllable by at least one predetermined parameter selected from among an output voltage of the buck converter, an output current of the buck converter, and a power of the buck converter.

5. The buck converter as recited in claim 1, wherein the switch (110) comprises at least one electronic switch.

6. The buck converter as recited in claim 1, wherein the diode (D1) is embodied in the form of an electronic switch.

7. The buck converter as recited in claim 5, wherein said at least one electronic switch is selected from the group comprising a transistor or at least one MOSFET, at least one thyristor, and at least one IGBT.

8. The buck converter as recited in claim 1, wherein the switch is triggered by a signal representing the sum of the first signal and the second signal.

9. The buck converter as recited in claim 8, wherein the sum of the first signal and the second signal is compared to the third signal.

10. The buck converter as recited in claim 1, wherein the first signal is a current signal that corresponds to the current through the electronic switch (110).

11. The buck converter as recited in claim 1, further including means for determining the additional voltage by peak value rectification of the voltage in the inductance using a retention time constant that is, in particular, greater than the line period.

12. The buck converter as recited in claim 11 further including means for an additional peak value rectification using a retention time constant that is less than the line period.

13. The buck converter as recited in claim 1, further including means for limiting on time duration of the switch (110) if the voltage in the inductance falls below a predeterminable minimum voltage.

14. The buck converter as recited in claim 13, wherein an online duration of the switch (110) is limited when the voltage in the inductance falls below the predeterminable minimum voltage.

15. A buck converter, comprising:

an input with a first connection (101) and second connection (102);

an output with a first connection (103) and second connection (104);

a switch (110);

a diode (D1) having a cathode and an anode;

an inductance (L1);

a capacitor (C1);

wherein the first connection (101) of the input is connected to the first connection (103) of the output via a series circuit comprised of the switch (110) and the inductance (L1);

the anode of the diode (D1) is connected to the connection between the switch (110) and the inductance (L1), the cathode of the diode (D1) is connected to the second connection (102) of the input and to the second connection (104) of the output, and the capacitor (C1) is connected in parallel with the first and second connections (103, 104) of the output, and such that the switch (110) is triggered from a first state to a second state by combining a first signal with a second signal,

wherein the switch is triggered by combining the first signal with the second signal and a third signal,

wherein the second signal is an essentially triangular shaped signal generated by a saw tooth generator, and

means for adding the current signal and the essentially triangular shaped signal by integration of a voltage in the inductance (L1) and an additional voltage.

16. The buck converter as recited in claim 15, wherein the first connection (101) of the input is of a negative polarity and the second connection 102 of the input is of a positive polarity.

17. The buck converter as recited in claim 15, wherein the third signal is a control variable from the output of the buck converter and is used to adjust the output signal of the buck converter and is substantially constant.

18. The buck converter as recited in claim 15, further including means for regulating, wherein the third signal is adjustable or controllable by at least one predetermined parameter selected from among an output voltage of the buck converter, an output current of the buck converter, and a power of the buck converter.

19. The buck converter as recited in claim 15, wherein the switch (110) comprises at least one electronic switch.

20. The buck converter as recited in claim 15, wherein the diode (D1) is embodied in the form of an electronic switch.

21. The buck converter as recited in claim 20, wherein said at least one electronic switch is selected from the group comprising a transistor or at least one MOSFET, at least one thyristor, and at least one IGBT.

22. The buck converter as recited in claim 15, wherein the switch is triggered by a signal representing the sum of the first signal and the second signal.

23. The buck converter as recited in claim 22, wherein the sum of the first signal and the second signal is compared to the third signal.

24. The buck converter as recited in claim 15, wherein the first signal is a current signal that corresponds to the current through the electronic switch (110).

25. The buck converter as recited in claim 15, further including means for determining the additional voltage by peak value rectification of the voltage in the inductance using a retention time constant that is, in particular, greater than the line period.

26. The buck converter as recited in claim 25, further including means for an additional peak value rectification using a retention time constant that is less than the line period.

27. The buck converter as recited in claim 15, further including means for limiting on time duration of the switch (110) if the voltage in the inductance falls below a predeterminable minimum voltage.

28. The buck converter as recited in claim 27, wherein an online duration of the switch (110) is limited when the voltage in the inductance falls below the predeterminable minimum voltage.