Switching power supply device and switching power supply system

• US 20060091870A1
• Filed: 12/16/2005
• Published: 05/04/2006
• Est. Priority Date: 06/07/2002
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Yoshida, Shinichi, Sase, Takashi, Tazawa, Tomohiro, Tateno, Kouji
• Granted Patent: US 7,091,711 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 3/1563 without using an external clock H02M3/158 takes precedence
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: H02M 3/3385 with automatic control of output voltage or current H02M3/33561 takes precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

There is provided a switching power supply device of hysteresis current mode control system which assures excellent response characteristic for change of output current and reduction of power consumption. In a switching regulator of hysteresis current mode control system, a sense resistor connected in series to a coil is eliminated, a serially connected resistor and a capacitor are connected in parallel to a coil in place of such sense resistor. Thereby, a potential of a connection node of these resistor and capacitor is inputted to a comparator circuit having the hysteresis characteristic for comparison with the reference voltage. Accordingly, a switch may be controlled for ON and OFF states.

Claims

1-25. -25. (canceled)

26. A switching power supply device comprising:

a first power supply terminal;

a second power supply terminal;

a switching element having a control terminal, a source terminal and a drain terminal, one of the source and drain terminals being coupled to the first power supply terminal;

an inductor having a first terminal coupled to the other of the source and drain terminals of the switching element and a second terminal;

a first capacitor having a first terminal coupled to the second terminal of the inductor and to be coupled to a load element and a second terminal coupled to the second power supply terminal;

a first resistor having a first terminal coupled to the other of the source and drain terminals of the switching element and a second terminal;

a second capacitor having a first terminal coupled to the second terminal of the first resistor and a second terminal coupled to the second terminal of the inductor; and

a hysteresis comparator having an input terminal coupled to the second terminal of the first resistor and an output terminal coupled to the control terminal of the switching element, the hysteresis comparator comparing a voltage received from the input terminal thereof with a first and a second threshold voltage relating to a hysteresis characteristic thereof and providing a discrimination result to the control terminal of the switching element.

44. The switching power supply device according to claim 26, wherein the hysteresis comparator outputs the discrimination result for the control terminal so as to control the voltage between the first threshold voltage and the second threshold voltage.

27. A semiconductor integrated circuit for a power supply device comprising:

a first node to which a first gate control signal for a first switching element is output, the first switching element having a control terminal, a source terminal and a drain terminal, the control terminal being coupled to the first node, and one of the source and the drain terminals being coupled to a first power supply terminal;

an inductor which has a first terminal and a second terminal, the first terminal of the inductor being coupled to the other of the source and drain terminals of the first switching element;

a first capacitor which has a first terminal to which a load element is to be coupled and a second terminal, the first terminal of the first capacitor being coupled to the second terminal of the inductor, the second terminal of the first capacitor being coupled to a second power supply terminal;

a first resistor which has a first terminal and a second terminal, the first terminal of the first resistor being coupled to the other of the source and the drain terminals of the first switching element;

a second capacitor which has a first terminal and a second terminal, the first terminal of the second capacitor being coupled to the second terminal of the first resistor, the second terminal of the second capacitor being coupled to the second terminal of the inductor;

a second node to which a second gate control signal for a second switching element is output, the second switching element having a control terminal, a source terminal and a drain terminal, the control terminal of the second switching element being coupled to the second node, one of the source and drain terminals of the second switching element being coupled to the other of the source and drain terminals of the first switching element, and the other of the source and drain terminals of the second switching element being coupled to the second power supply terminal; and

a hysteresis comparator, which has an input terminal coupled to the second terminal of the first resistor and an output terminal, and which compares a first voltage received from the input terminal thereof with a first and a second threshold voltage relating to a hysteresis characteristic thereof and provides a discrimination result for first and the second nodes.

45. The semiconductor integrated circuit for the power supply device according to claim 27, wherein the hysteresis comparator outputs the discrimination result so as to control the first voltage between the first threshold voltage and the second threshold voltage.

48. The semiconductor integrated circuit for the power supply device according to claim 27, further comprising a switching control circuit which is coupled to the output terminal of the hysteresis comparator and the first and the second nodes and which outputs the first and second control gate signals based on the discrimination result.

28. A power supply device, comprising:

a power supply terminal;

a ground terminal;

a P-channel MOSFET which has a control terminal, a source terminal coupled to the power supply terminal, and a drain terminal;

an N-channel MOSFET which has a control terminal, a source terminal coupled to the ground terminal, and a drain terminal coupled to the drain terminal of the P-channel MOSFET;

an inductor having a first terminal coupled to the drain terminal of the P-channel MOSFET and a second terminal;

a first capacitor having a first terminal coupled to the second terminal of the inductor and to be coupled to a load element and a second terminal coupled to the ground terminal;

a first resistor having a first terminal coupled to the drain terminal of the P-channel MOSFET and a second terminal;

a second capacitor having a first terminal coupled to the second terminal of the first resistor and a second terminal coupled to the second terminal of the inductor;

a second resistor having a first terminal coupled to a second terminal of the first resistor and a second terminal;

a hysteresis comparator having a first input terminal coupled to the second terminal of the first resistor and an output terminal, the hysteresis comparator comparing a first voltage received from the first input terminal thereof with a first and a second threshold voltage; and

a switching control circuit which receives a discrimination result from the output terminal of the hysteresis comparator and controls the control terminals of the P-channel and the N-channel MOSFET based on the discrimination result.

29. The power supply device according to claim 28, further comprising:

a third resistor having a first terminal coupled to the first terminal of the first capacitor and a second terminal;

a fourth resistor having a first terminal coupled to the second terminal of the third resistor and a second terminal coupled to the ground terminal; and

an error amp having a first input terminal which receives a second voltage from the second terminal of the third resistor, a second input terminal which receives a first reference voltage and an output terminal outputting an output signal to a second input terminal of the hysteresis comparator,

wherein the second terminal of the second resistor is coupled to the ground terminal.

30. The power supply device according to claim 28, wherein a predetermined voltage is input to a second input terminal of the hysteresis comparator.

31. The power supply device according to claim 30, wherein the second terminal of the second resistor is coupled to the ground terminal.

46. The power supply device according to claim 28, wherein the hysteresis comparator outputs the discrimination result so as to control the first voltage between the first threshold voltage and the second threshold voltage.

32. A power supply device, comprising:

a power supply terminal;

a ground terminal;

a first N-channel MOSFET which has a control terminal, a source terminal, and a drain terminal which is coupled to the power supply terminal;

a second N-channel MOSFET which has a control terminal, a source terminal coupled to the ground terminal, and a drain terminal which is coupled to the source terminal of the first N-channel MOSFET;

an inductor having a first terminal coupled to the source terminal of the first N-channel MOSFET and a second terminal;

a first capacitor having a first terminal coupled to the second terminal of the inductor and to be coupled to a load element and a second terminal coupled to the ground terminal;

a first resistor having a first terminal coupled to the source terminal of the first N-channel MOSFET and a second terminal;

a second capacitor having a first terminal coupled to the second terminal of the first resistor and a second terminal coupled to the second terminal of the inductor;

a second resistor having a first terminal coupled to the second terminal of the first resistor and a second terminal;

a hysteresis comparator having a first input terminal coupled to the second terminal of the first resistor and an output terminal, the hysteresis comparator comparing a first voltage received from the first input terminal thereof with a first and a second threshold voltage; and

a switching control circuit which receives a discrimination result from the output terminal of the hysteresis comparator and controls the control terminals of the MOSFETs based on the discrimination result.

33. The power supply device according to claim 32, further comprising:

a third resistor having a first terminal coupled to the first terminal of the first capacitor and a second terminal;

a fourth resistor having a first terminal coupled to the second terminal of the third resistor and a second terminal coupled to the ground terminal; and

an error amp having a first input terminal which receives a second voltage from the second terminal of the third resistor, a second input terminal which receives a first reference voltage and an output terminal outputting an output signal to a second input terminal of the hysteresis comparator,

wherein the second terminal of the second resistor is coupled to the ground terminal.

34. The power supply device according to claim 32, wherein a predetermined voltage is input to a second terminal of the hysteresis comparator.

35. The power supply device according to claim 32, wherein the second terminal of the second resistor is coupled to the ground terminal.

47. The semiconductor integrated circuit for the power supply device according to claim 32, wherein the hysteresis comparator outputs the discrimination result so as to control the first voltage between the first threshold voltage and the second threshold voltage.

36. A semiconductor integrated circuit for a power supply device comprising:

a first node to which a first gate control signal for a P-channel MOSFET is output, the P-channel MOSFET having a control terminal coupled to the first node, a source terminal coupled to a first power supply terminal, and a drain terminal;

an inductor having a first terminal coupled to the drain terminal of the P-channel MOSFET;

a first capacitor having a first terminal coupled to a second terminal of the inductor and to which load element is to be coupled, and a second terminal coupled to a second power supply terminal;

a first resistor having a first terminal coupled to the drain terminal of the P-channel MOSFET and a second terminal;

a second capacitor having a first terminal coupled to the second terminal of the first resistor, and a second terminal coupled to the second terminal of the inductor;

a second resistor having a first terminal coupled to the second terminal of the first resistor;

a second node to which a second gate control signal for an N-channel MOSFET is output, the N-channel MOSFET having a control terminal coupled to the second node, a drain terminal coupled to the drain terminal of the P-channel MOSFET, and a source terminal coupled to the second power supply terminal;

a hysteresis comparator which has a first input terminal coupled to the second terminal of the first resistor and an output terminal, which compares a first voltage received from the input terminal thereof with a first threshold voltage and a second threshold voltage larger than the first threshold voltage, and which outputs a discrimination result; and

a switching control circuit which is coupled to the first and second nodes and the output node of the hysteresis comparator, and which outputs the first gate control signal to the first node based on the discrimination result received from the hysteresis comparator and outputs the second gate control signal to the second node based on the discrimination result.

37. The semiconductor integrated circuit for the power supply device according to claim 36, further comprising:

an error amp having a first input terminal which receives a second voltage from a first terminal of a third resistor, the third resistor having a second terminal coupled to the first terminal of the first capacitor;

a fourth resistor having a first terminal coupled to the first terminal of the third resistor and a second terminal coupled to the second power supply terminal,

the error amp having a second input terminal receiving a first reference voltage, and an output terminal providing an output signal to a second input terminal of the hysteresis comparator,

wherein a second terminal of the second resistor is coupled to the second power supply terminal.

38. The semiconductor integrated circuit for a power supply device according to claim 36,

wherein a predetermined voltage is input to a second terminal of the hysteresis comparator.

39. The semiconductor integrated circuit for the power supply device according to claim 38, wherein a second terminal of the second resistor is coupled to the second power supply terminal.

40. A semiconductor integrated circuit for a power supply device comprising:

a first node to which a first gate control signal for a first N-channel MOSFET is output, the first N-channel MOSFET having a control terminal coupled to the first node, a drain terminal coupled to a first power supply terminal, and a source terminal;

an inductor having a first terminal coupled to the source terminal of the first N-channel MOSFET and a second terminal;

a first capacitor having a first terminal coupled to the second terminal of the inductor and to which a load element is to be coupled, and a second terminal coupled to a second power supply terminal;

a first resistor having a first terminal coupled to the source terminal of the first N-channel MOSFET and a second terminal;

a second capacitor having a first terminal coupled to the second terminal of the first resistor and a second terminal coupled to the second terminal of the inductor;

a second resistor having a first terminal coupled to the second terminal of the first resistor;

a second node to which a second gate control signal for a second N-channel MOSFET is output, the second N-channel MOSFET having a control terminal coupled to the second node, a drain terminal coupled to the source terminal of the first N-channel MOSFET, and a source terminal coupled to the second power supply terminal;

a hysteresis comparator which has a first input terminal coupled to the second terminal of the first resistor and an output terminal, which compares a first voltage received from the input terminal thereof with a first threshold voltage and a second threshold voltage larger than the first threshold voltage, and which outputs a discrimination result; and

a switching control circuit which is coupled to the first and second nodes and an output of the hysteresis comparator, and which outputs the first gate control signal to the first node based on the discrimination result received from the hysteresis comparator and outputs the second gate control signal to the second node based on the discrimination result.

41. The semiconductor integrated circuit for the power supply device according to claim 40, further comprising:

an error amp having a first input terminal which receives a second voltage from a first terminal of a third resistor, the third resistor having a second terminal coupled to the first terminal of the first capacitor;

a fourth resistor having a first terminal coupled to the first terminal of the third resistor and a second terminal coupled to the second power supply terminal,

the error amp having a second input terminal receiving a first reference voltage, and an output terminal providing an output signal to a second input terminal of the hysteresis comparator,

wherein a second terminal of the second resistor is coupled to the second power supply terminal.

42. The semiconductor integrated circuit for a power supply device according to claim 40,

wherein a predetermined voltage is input to a second terminal of the hysteresis comparator.

43. The semiconductor integrated circuit for the power supply device according to claim 40, wherein a second terminal of the second resistor is coupled to the second power supply terminal.