Power converter circuitry and method

• US 6,917,188 B2
• Filed: 11/14/2002
• Issued: 07/12/2005
• Est. Priority Date: 11/14/2002
• Status: Expired due to Term

• Current Assignee: Exar Corporation (Maxlinear Incorporated)
• Original Assignee: FYRE Storm Incorporated (Maxlinear Incorporated)
• Inventors: Kernahan, Kent
• Primary Examiner(s): Patel, Rajnikant B.
• Application Number:
  US10/295,980
• Publication Number:
  US 20040095118A1
• Time in Patent Office: 971 Days
• Field of Search: 323/282, 323/285, 323/286, 323/287, 363/89, 363/127, 363/96, 363/129, 363/81, 363/87, 361/91.7, 361/56, 361/86, 361/23
• US Class Current: 323/282
• CPC Class Codes: G05F 3/262 using field-effect transistors only
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02M 1/0012 Control circuits using digital or numerical techniques in DC/DC converters H02M3/157, H02M3/33515; in DC-AC converters H02M7/53873
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• 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 1/0845 digitally controlled (or with digital control)
• 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 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: H03M 5/08 Code representation by pulse width
• CPC Class Codes: H05B 41/2828 using control circuits for the switching elements H05B41/2827 takes precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• 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 switching power supply controller coupled to a first switching power supply circuit and a second switching power supply circuit, the controller sensing voltages provided to the first switching power supply circuit and the second switching power supply circuit. Based on voltages sensed, the switching power supply controller provides signals to operate the second switching power supply in either a first or a second mode of operation. In one of the modes of operation, the second switching power supply includes a transistor which is coupled between a first source of electrical potential and an input terminal of the first switching power supply. If switching power supply controller determines that the magnitude of the first source of electric potential is sufficient to operate the first switching power supply, the switching power supply controller provides a control signal to turn on the transistor continuously.

Claims

1. A switching power supply system comprising:

a first switching power supply circuit having an input terminal for receiving an input voltage and providing a selected output at an output terminal;

a second switching power supply circuit including a first input terminal connected to a first source of electrical potential, and having an output terminal coupled to the input terminal of the first switching power supply, for providing a voltage to the input terminal of the first switching power supply;

a switching power supply controller having a first set of terminals coupled to the first switching power supply for providing control signals to the first switching power supply, a second set of terminals coupled to the first switching power supply for receiving information from the first switching power supply, a third set of terminals for providing control signals to the second switching power supply, and at least one terminal for receiving information from the second switching power supply, wherein the switching power supply controller is configured to provide one or more control signals to the second switching power supply to operate the second switching power supply in a first mode where the magnitude of the voltage provided by the first source of electrical potential is determined by the switching power supply controller to be sufficient to operate the first switching power supply to provide the selected output from the first switching power supply, and further wherein the switching power supply controller is configured to provide control signals to the second switching power supply to operate the second switching power supply in a second, different mode when the switching power supply controller determines that the magnitude of the first source of electrical potential is insufficient to operate the first switching power supply to provide the selected output.

2. The switching power supply system according to claim 1, wherein the second switching power supply comprises a transistor coupled between the first source of electrical potential and the input terminal of the first switching power supply, and wherein the switching power supply controller provides a control signal to turn the transistor on continuously during a time in which the switching power supply controller determines that the magnitude of the first source of electrical potential is sufficient to permit the first switching power supply to provide the selected output its output terminal.

3. The switching power supply system according to claim 1, wherein in the second mode the control signals configure the second switching power supply to operate as a boost supply.

4. The switching power supply system according to claim 1, wherein the first source of electrical potential is a battery, wherein the system includes a second input terminal connected to a second source of electrical potential having a magnitude greater than the magnitude of a fully charged output potential of the battery, and further wherein if the switching power supply controller determines that based on a detected output voltage of the battery that a charging of the battery is desirable, the switching power supply controller provides control signals to the second switching power supply to configure the second switching power supply as a buck supply to charge the battery.

5. The switching power supply system according to claim 1, wherein the first source of electrical potential is a battery.

6. The switching power supply system according to claim 2, wherein the first source of electrical potential is a battery.

7. The switching power supply system according to claim 3, wherein the first source of electrical potential is a battery.