Implementing voltage sense point switching for regulators

Patent metadata

Field	Value
Publication number	US-10340785-B2
Application number	US-201816035599-A
Country	US
Kind code	B2
Filing date	Jul 14, 2018
Priority date	Jun 13, 2017
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

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.

First claim

What is claimed is:

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.

Assignees

• IBM

Inventors

• Berge Layne A
• Egan Patrick K

Classifications

• H02M1/32 Primary

  Means for protecting converters other than automatic disconnection · CPC title

• H02M2001/0054

  Electricity · mapped topic

• H03K17/0822 Primary

  in field-effect transistor switches · CPC title

• H03K17/165

  by feedback from the output circuit to the control circuit · CPC title

• H03K2217/0027

  Measuring means of, e.g. currents through or voltages across the switch · CPC title