Implementing voltage sense point switching for regulators

• US 10,340,785 B2
• Filed: 07/14/2018
• Issued: 07/02/2019
• Est. Priority Date: 06/13/2017
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Berge, Layne A., Egan, Patrick K.
• Primary Examiner(s): Zhang, Jue
• Assistant Examiner(s): Lee, Jye-June
• Application Number:
  US16/035,599
• Publication Number:
  US 20180358892A1
• Time in Patent Office: 353 Days
• CPC Class Codes: H02M 1/0054 Transistor switching losses periodically suspending operation of switching converter in low power mode H02M1/0035
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H03K 17/0822 in field-effect transistor switches
• CPC Class Codes: H03K 17/165 by feedback from the output circuit to the control circuit
• CPC Class Codes: H03K 2217/0027 Measuring means of, e.g. currents through or voltages across the switch
• 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 and circuit are provided for implementing voltage sense point switching for regulators. A regulator voltage sensing circuit includes at least two sense points enabling a regulator to compensate for voltage drop at the sense points and providing at least one of the sense points at a location to be switched. Switched loads have gains at the sense points to compensate for the voltage drop in a transistor switch at maximum load. A non-switched output is sensed and functions as an over-voltage protection to limit the transistor switch voltage drop.

Claims

1. A method for implementing voltage sense point switching for regulators comprising:

providing a first sense point at a non-switched sense location, said first sense point being always on;

providing a second sense point at a location to be switched;

said second sense point optionally being switched off controlled using a transistor switch;

providing a first operational amplifier coupled to said first sense point and a second operational amplifier coupled to said second sense point, and connecting a first diode to an output of said first operational amplifier and connecting a second diode to an output of said second operational amplifier;

providing a circuit output at said first and second diodes to a remote sense input to a regulator;

providing switched loads having gains at each of said first and second sense points to make up for a voltage drop in said transistor switch at maximum load; and

said first sense point functioning as an over-voltage protection to limit the voltage drop in said transistor switch.

2. The method as recited in claim 1, includes providing said transistor switch with a field effect transistor (FET) switch connected between said first sense point and said second sense point.

3. The method as recited in claim 2, includes providing an N-channel field effect transistor (NFET) switch.

4. The method as recited in claim 3, includes turning off said NFET switch with a gate drive to said NFET switch.

5. The method as recited in claim 1, includes turning off said transistor switch and only sensing said first sense point.

6. The method as recited in claim 5, includes providing said circuit output with a higher of said first sense point and said second sense point.

7. The method as recited in claim 1, includes providing 0 volts loss across each of said first and second diodes using compensation with said first and second operational amplifiers.

8. The method as recited in claim 1, includes providing biasing and feedback resistors with each said first and second operational amplifiers to compensate for loss across said transistor switch and to avoid an over-voltage condition.

9. The method as recited in claim 1, includes sensing only said second sense point until said transistor switch is turned back on and its voltage exceeds a threshold value.

10. A circuit for implementing voltage sense point switching for regulators comprising:

a first sense point provided at a non-switched sense location, said first sense point being always on;

a second sense point provided at a location to be switched;

said second sense point optionally is switched off controlled using a transistor switch;

said first sense point coupled to a first operational amplifier and a first diode connected to an output of said first operational amplifier and said second sense point coupled to a second operational amplifier and a second diode connected to an output of said second operational amplified;

a circuit output of said first and second diodes providing a remote sense to a regulator;

switched loads having gains at each of said first and second sense points to make up for a voltage drop in said transistor switch at maximum load; and

said first sense point functions as an over-voltage protection to limit the voltage drop in said transistor switch.

11. The circuit as recited in claim 10, wherein said transistor switch includes a field effect transistor (FET) switch.

12. The circuit as recited in claim 10, wherein said transistor switch includes an N-channel field effect transistor (NFET) switch.

13. The circuit as recited in claim 10, wherein said transistor switch is connected between said first sense point and said second sense point.

14. The circuit as recited in claim 10, wherein said transistor switch is controlled by a gate drive input.

15. The circuit as recited in claim 10, wherein said transistor switch is turned off for only sensing said first sense point.

16. The circuit as recited in claim 10, wherein said first and second operational amplifiers each include biasing and feedback resistors to compensate for loss across said transistor switch and to avoid an over-voltage condition.