Method of driving a power converter by using a power pulse and a sense pulse

• US 6,894,911 B2
• Filed: 11/27/2002
• Issued: 05/17/2005
• Est. Priority Date: 06/02/2000
• Status: Expired due to Term

• Current Assignee: Dialog Semiconductor Incorporated (Renesas Electronics Corporation)
• Original Assignee: iWatt, Inc. (Renesas Electronics Corporation)
• Inventors: Geber, Charles R., Wong, Dickson T., Muegge, Mark R., Telefus, Mark D.
• Primary Examiner(s): STERRETT, JEFFREY L
• Application Number:
  US10/306,780
• Publication Number:
  US 20030128018A1
• Time in Patent Office: 902 Days
• Field of Search: 323/222, 323/282, 323/283, 363/21.04, 363/21.05, 363/21.08, 363/21.1, 363/21.11, 363/21.12, 363/21.13, 363/21.16, 363/21.18, 363/97
• US Class Current: 363/97
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/0041 Control circuits in which a clock signal is selectively enabled or disabled
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/157 with digital control
• CPC Class Codes: H02M 3/33515 with digital control
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• 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

A method of regulating voltage at an output of a switching power converter, the converter comprising a switch and pulse generation circuitry, the pulse generation circuitry producing one or more drive signals for cycling the switch ON and OFF, wherein if the switch is cycled ON and OFF according to a cycle of a drive signal, power is transferred from a source to a load. The method includes sensing an output voltage feedback signal, comparing the sensed feedback signal to a reference at a determined time during a cycling of the switch, and regulating an output voltage at the load by controlling whether a cycle of one of the drive signals cycles the switch in response to the comparison.

Claims

1. A method of regulating voltage at an output of a switching cower converter, the converter comprising a switch and pulse generation circuitry, the pulse generation circuitry producing one or more drive signals for cycling the switch ON and OFF to transfer power from a source to a load, the method comprising:

sensing an output voltage feedback signal;

comparing the sensed feedback signal to a reference at a determined time during the cycling of the switch; and

regulating an output voltage at the load by controlling whether a cycle of one of the drive signals cycles the switch in response to the comparison, the step of regulating the output voltage including;

producing a first drive signal using a first pulse generator of the pulse generation circuitry for cycling the switch ON and OFF, wherein if the switch is cycled ON and OFF according to a cycle of the first drive signal, a power pulse is transferred from the source to the load, and

producing a second drive signal using a second pulse generator of the pulse generation circuitry for cycling the switch ON and OFF, wherein if the switch is cycled ON and OFF according to a cycle of the second drive signal, a sense pulse is transferred from the source to the load, the power transferred to the load by the sense pulse being substantially less than the power transferred to the load by the power pulse,

wherein the cycling of the switch is enabled by a cycle of the power pulse, the sense pulse, or neither, in response to the comparison, and the comparison of the sensed feedback signal to the reference made during one or more previous switch cycles is taken into account in determining whether to enable the cycle of the power pulse, the sense pulse, or neither, to cycle the switch in response to a present comparison.

2. A method of regulating voltage at an output of a switching power converter, the converter comprising a switch and pulse generation circuitry, the pulse generation circuitry producing one or more drive signals for cycling the switch ON and OFF to transfer power from a source to a load, the method comprising:

sensing an output voltage feedback signal originating from a primary side of the converter, the sensed feedback signal approximating an output voltage at the load;

comparing the sensed feedback signal to a reference at an instant when the sensed feedback signal corresponds to the output voltage plus a small, substantially constant voltage drop measured from cycle to cycle of the switch; and

regulating the output voltage by controlling whether a cycle of one of the drive signals cycles the switch in response to the comparison, the step of regulating the output voltage including;

producing a first drive signal using a first pulse generator of the pulse generation circuitry for cycling the switch ON and OFF, wherein if the switch is cycled ON and OFF according to a cycle of the first drive signal, a power pulse is transferred from the source to the load, and

producing a second drive signal using a second pulse generator of the pulse generation circuitry for cycling the switch ON and OFF, wherein if the switch is cycled ON and OFF according to a cycle of the second drive signal, a sense pulse is transferred from the source to the load, the power transferred to the load by the sense pulse being substantially less than the power transferred to the load by the power pulse,

wherein the cycling of the switch is enabled by a cycle of the power pulse, the sense pulse, or neither, in response to the comparison, and the comparison of the sensed feedback signal to the reference made during one or more previous switch cycles is taken into account in determining whether to enable the cycle of the power pulse, the sense pulse, or neither, to cycle the switch in response to a present comparison.