Devices and methods for voltage supply monitoring

Patent metadata

Field	Value
Publication number	US-11422201-B1
Application number	US-202117205056-A
Country	US
Kind code	B1
Filing date	Mar 18, 2021
Priority date	Mar 18, 2021
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

An integrated circuit, can comprise a first power supply terminal configured to supply a first voltage, a second power supply terminal configured to supply a second voltage, a first supply monitor including a detector having a first input and a second input, and configured to provide a fault indicator based on a comparison between the first and second inputs, and switching circuitry configured to during a normal operating mode, couple a voltage derived from the first voltage to the first input and a voltage derived from the second voltage to the second input, and during a self-test mode, couple the voltage derived from the second voltage to the first input and the voltage derived from the first voltage to the second input.

First claim

What is claimed is:

1. An integrated circuit, comprising:
a first power supply terminal configured to supply a first voltage;
a second power supply terminal configured to supply a second voltage;
a first supply monitor including:
a detector having a first input and a second input, and configured to provide a fault indicator based on a comparison between the first and second inputs, and
switching circuitry configured to:
during a normal operating mode, couple a voltage derived from the first voltage to the first input and a voltage derived from the second voltage to the second input ( ), and
during a self-test mode, couple the voltage derived from the second voltage to the first input and the voltage derived from the first voltage to the second input.

2. The integrated circuit of claim 1 , wherein the detector is configured to assert the fault indicator when a voltage at the first input is greater than a voltage at the second input, and negate the fault indicator when the voltage at the first input is less than the voltage at the second input.

3. The integrated circuit of claim 1 , further comprising:
a first scaling circuit configured to scale the first voltage using a first scaling factor to provide a first scaled voltage to the detector as the voltage derived from the first voltage; and
a second scaling circuit configured to scale the second voltage using a second scaling factor to provide a second scaled voltage to the detector as the voltage derived from the second voltage, wherein the first scaling factor is less than the second scaling factor.

4. The integrated circuit of claim 3 , wherein the first scaling factor is less than one and the second scaling factor is one such that the second voltage is provided unscaled as the second scaled voltage.

5. The integrated circuit of claim 3 , wherein the first scaling factor is at most 0.8.

6. The integrated circuit of claim 1 , wherein the first and second power supply terminals are configured to receive a same supply voltage from a power source external to the integrated circuit.

7. The integrated circuit of claim 1 , further comprising a first subcircuit and a second subcircuit, wherein the first power supply terminal is configured to supply the first voltage to the first subcircuit, and the second power supply terminal is configured to supply the second voltage to the second subcircuit.

8. The integrated circuit of claim 7 , further comprising a precision supply monitor having a first input coupled to receive the first voltage from the first power supply terminal, a second input coupled to receive a reference voltage, and an output which indicates whether the first voltage is within an expected voltage range.

9. The integrated circuit of claim 1 , further comprising a test control circuit configured to monitor the fault indicator, wherein during the self-test mode, upon coupling the voltage derived from the second voltage to the first input and the voltage derived from the first voltage to the second input:
if the fault indicator does not change state, the test control circuit is configured to indicate a self-test fail, and
if the fault indicator changes state, the test control circuit is configured to indicate a self-test pass.

10. The integrated circuit of claim 1 , further comprising:
a third power supply terminal configured to supply a third voltage;
a second supply monitor including:
a second detector having a first input and a second input, and configured to provide a second fault indicator based on a comparison between the first and second inputs of the second detector, and
second switching circuitry configured to:
during the normal operating mode, couple the voltage derived from the first voltage to the first input of the second detector and a voltage derived from the third voltage to the second input of the second detector, and
during the self-test mode, couple the voltage derived from the third voltage to the first input of the second detector and the voltage derived from the first voltage to the second input of the second detector.

11. An integrated circuit, comprising:
a first power supply terminal configured to supply a first supply voltage to a first subcircuit;
a plurality of power supply terminals each configured to supply a corresponding supply voltage to a corresponding subcircuit;
a primary supply monitor having a first input coupled to receive the first supply voltage from the first power supply terminal, a second input coupled to receive a reference voltage, and an output which indicates whether the first voltage is within an expected voltage range;
a plurality of secondary supply monitors, each secondary supply monitor corresponding to a power supply terminal of the plurality of power supply terminals and including:
a corresponding detector having a first input and a second input, and configured to provide a corresponding fault indicator based on a comparison between the first and second inputs of the corresponding detector, and
switching circuitry configured to:
during a normal operating mode, couple a voltage derived from the first supply voltage to the first input of the corresponding detector and a voltage derived from the corresponding supply voltage to the second input of the corresponding detector, and
during a self-test mode, couple the voltage derived from the corresponding supply voltage to the first input of the corresponding detector and the voltage derived from the first supply voltage to the second input of the corresponding detector.

12. The integrated circuit of claim 11 , further comprising:
test control circuitry configured to monitor the corresponding fault indicators, wherein, for each secondary supply monitor of the plurality of secondary supply monitors, during the self-test mode, upon coupling the voltage derived from the corresponding supply voltage to the first input of the corresponding detector and the voltage derived from the first voltage to the second input of the corresponding detector:
if the corresponding fault indicator does not change state, the test control circuit is configured to indicate a corresponding self-test fail, and
if the corresponding fault indicator changes state, the test control circuit is configured to indicate a corresponding self-test pass.

13. The integrated circuit of claim 11 , further comprising:
a first scaling circuit configured to scale the first supply voltage using a first scaling factor to provide a first scaled voltage to the detector as the voltage derived from the first supply voltage; and
a plurality of scaling circuits corresponding to the plurality of power supply terminals, wherein each scaling circuit of the plurality of scaling circuits is configured to scale the corresponding supply voltage using a corresponding scaling factor to provide a corresponding scaled voltage to the corresponding detector as the voltage derived from the corresponding supply voltage, wherein the first scaling factor is less than each of the corresponding scaling factors.

14. The integrated circuit of claim 13 , wherein the first scaling factor is at most 80%, and each of the corresponding scaling factors is at least 90%.

15. The integrated circuit of claim 11 , wherein the first power supply terminal and each of the plurality of power supply terminals are configured to receive a same supply voltage from a power source external to the integrated circuit.

16. A method, in an integrated circuit having a first power supply terminal configured to supply a first voltage, and a second power supply terminal configured to supply a second voltag

Assignees

• Nxp Usa Inc

Inventors

• Raschbacher Sebastian
• Bode Hubert Martin
• Lehmann Mark
• Shen Xianghua

Classifications

• G01R31/40 Primary

  Testing power supplies (testing photovoltaic devices H02S50/10) · CPC title

• G01R19/16552

  in I.C. power supplies · CPC title

• G05F1/46 Primary

  wherein the variable actually regulated by the final control device is DC (G05F1/625 takes precedence) · CPC title

• G01R19/10

  Measuring sum, difference or ratio · CPC title