Step-up regulator with multiple power sources for the controller

• US 7,714,546 B2
• Filed: 02/12/2007
• Issued: 05/11/2010
• Est. Priority Date: 03/08/2006
• Status: Expired due to Fees

• Current Assignee: Collabo Innovations, Inc. (Wi-LAN Inc.)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kimura, Kazuhito, Ishii, Takuya
• Primary Examiner(s): Riley, Shawn
• Application Number:
  US11/705,013
• Publication Number:
  US 20070210774A1
• Time in Patent Office: 1,184 Days
• Field of Search: 323/222, 323/283, 323/266, 323/298
• US Class Current: 323/222
• CPC Class Codes: H02M 1/0006 Arrangements for supplying an adequate voltage to the control circuit of converters
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 3/073 Charge pumps of the Schenkel-type
• CPC Class Codes: H02M 3/155 using semiconductor devices only
• CPC Class Codes: H03K 2217/0081 Power supply means, e.g. to the switch driver

Abstract

An output voltage VC obtained by boosting an input voltage VIN by means of a charge pump control circuit 3 of a charge pump 102 is supplied as a power supply voltage to a control circuit 4 of a step-up converter. It is thus possible to eliminate the need for a conventional self-bias method, eliminate switching from startup oscillation to main oscillation of the conventional self-bias method upon startup, and overcome problems caused by the switching of oscillation states, thereby achieving switching power supply circuitry starting in a reliable and stable manner.

Claims

1. Switching power supply circuitry, comprising:

a step-up converter for switching a DC input voltage by means of a switch element to obtain a DC output voltage boosted from the input voltage,

a step-up power supply for a control circuit, the step-up power supply for a control circuit for boosting the input voltage and outputting a second boosted voltage, and

a control circuit supplied with power at the second boosted voltage from the step-up power supply for a control circuit, the control circuit for controlling the switch element of the step-up converter when the second boosted voltage from the step-up power supply for a control circuit is equal to or higher than a predetermined operation start voltage, wherein only the output voltage of the step-up converter is supplied to a load.

2. The switching power supply circuitry according to claim 1, wherein the step-up power supply for a control circuit comprises:

an oscillation circuit for generating driving pulses of a predetermined frequency,

a plurality of second switch elements for switching in response to the driving pulses, and

at least a single jumping capacitor charged/discharged by switching of the plurality of second switch elements.

3. The switching power supply circuitry according to claim 2, wherein the oscillation circuit is a ring oscillation circuit including inverters of multiple stages connected like a ring.

4. The switching power supply circuitry according to claim 2, wherein the step-up power supply for a control circuit comprises a stabilizing circuit for stabilizing the second boosted voltage.

5. The switching power supply circuitry according to claim 4, wherein the stabilizing circuit is a series regulator.

6. The switching power supply circuitry according to claim 1, wherein the control circuit comprises:

an error amplifier for comparing the output voltage of the step-up converter with a target value and generating an error signal and

a PWM circuit for generating a driving pulse for controlling a switching operation of the step-up converter in response to the error signal,

wherein when the output voltage of the step-up converter is equal to or higher than a predetermined value, at least one of the error amplifier and the PWM circuit is supplied with power from the output voltage of the step-up converter not from the second boosted voltage of the step-up power supply for a control circuit.

7. The switching power supply circuitry according to claim 1, wherein when the output voltage of the step-up converter is equal to or higher than a predetermined value, the control circuit is supplied with power from the output voltage of the step-up converter not from the second boosted voltage of the step-up power supply for a control circuit.

8. The switching power supply circuitry according to claim 7, wherein the step-up power supply for a control circuit is for stopping operation when the output voltage of the step-up converter is equal to or higher than the predetermined value.

9. The switching power supply circuitry according to claim 1, further comprising:

a DC-DC converter for obtaining a second output voltage from the DC input voltage, and

a second control circuit supplied with power from the second boosted voltage of the step-up power supply for a control circuit, the second control circuit for controlling the DC-DC converter when the second boosted voltage of the step-up power supply for a control circuit reaches the predetermined operation start voltage.