Integration of analog circuits inside digital blocks

Patent metadata

Field	Value
Publication number	US-11258447-B2
Application number	US-202016796405-A
Country	US
Kind code	B2
Filing date	Feb 20, 2020
Priority date	Feb 20, 2020
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

A circuit for sensing local operating properties of an integrated circuit is disclosed. The circuit may include one or more sensor circuits configured to sense the local operating properties of the integrated circuit. The sensor circuits may receive a supply voltage with a magnitude in a limited range from a digital power supply that is different from the digital power supply that provides power to functional circuits in the integrated circuit. Level shifters may be coupled to the sensor circuits to shift output signals from the sensor circuits to levels that correspond to the digital power supply that provides power to functional circuits in the integrated circuit. Counters and a shift register may be coupled to the level shifters to receive the shifted output signals, the values of which may be used to determine the local operating properties of the integrated circuit as sensed by the sensor circuits.

First claim

What is claimed is:

1. A circuit, comprising:
a first digital power supply that provides a first supply voltage to first digital functional circuitry during use, wherein the first supply voltage is varied during use based on one or more operating properties of the first digital functional circuitry;
a second digital power supply, wherein the second digital power supply provides a supply voltage with a magnitude in a limited range to second digital functional circuitry during use, and wherein the supply voltage with the magnitude in the limited range is not varied during use based on one or more operating properties of the second digital functional circuitry;
a first circuit configured to assess one or more local operating properties, wherein the first circuit includes:
a first sensor circuit coupled to the second digital power supply, wherein the first sensor circuit is configured to provide an output signal responsive to a value of a first local operating property of the first digital functional circuitry;
a first level shifter coupled to the first sensor circuit, the first level shifter being configured to receive the output signal from the first sensor circuit and provide a first shifted output signal corresponding to the first supply voltage; and
a first counter coupled to the first level shifter, wherein the first counter is configured to receive the first shifted output signal and capture a first value representing the first shifted output signal.

2. The circuit of claim 1 , further comprising a shift register coupled to receive the first value from the first counter.

3. The circuit of claim 1 , wherein the first sensor circuit includes a ring oscillator coupled to the second digital power supply, the ring oscillator being configured to provide the output signal responsive to the value of the first local operating property.

4. The circuit of claim 3 , wherein the first counter is configured to determine the first value based on a frequency of the first shifted output signal received from the ring oscillator in the first sensor circuit.

5. The circuit of claim 1 , wherein the first circuit comprises a second sensor circuit coupled to the second digital power supply, wherein the second sensor circuit is configured to provide an output signal responsive to a value of a second local operating property of the first digital functional circuitry, wherein the second local operating property is different from the first local operating property.

6. The circuit of claim 5 , further comprising:
a second level shifter coupled to the second sensor circuit, the second level shifter configured to receive the output signal from the second sensor circuit and provide a second shifted output signal corresponding to the first supply voltage; and
a second counter coupled to the second level shifter.

7. The circuit of claim 5 , wherein the second sensor circuit includes a ring oscillator coupled to the second digital power supply, the ring oscillator being configured to provide the output signal responsive to the value of the second local operating property.

8. The circuit of claim 5 , wherein a circuit topology of the first sensor circuit is sensitive to variations in voltage, and wherein a circuit topology of the second sensor circuit is sensitive to variations in temperature.

9. The circuit of claim 6 , wherein the second counter is configured to receive the second shifted output signal and capture a second value representing the second shifted output signal.

10. The circuit of claim 1 , wherein the supply voltage with the magnitude in the limited range is a supply voltage with a substantially fixed magnitude.

11. The circuit of claim 1 , further comprising a ring oscillator coupled to the first digital power supply, wherein the ring oscillator is configured to assess a local aging property, and wherein the ring oscillator is coupled to the first counter.

12. A method comprising:
receiving, at a first sensor circuit, a first supply voltage from a first digital power supply, wherein the first digital power supply provides the first supply voltage at a supply voltage with a magnitude in a limited range, the first supply voltage not being varied based on one or more operating properties of a first digital functional circuitry coupled to the first digital power supply, and wherein the first sensor circuit produces an output signal responsive to a value of a first local operating property of a second digital functional circuitry coupled to the first sensor circuit;
shifting a level of the output signal using a first level shifter coupled to the first sensor circuit, wherein the shifted output signal is shifted corresponding to a second supply voltage provided by a second digital power supply coupled to the second digital functional circuitry, the second digital supply voltage being varied based on one or more operating properties of the second digital functional circuitry;
receiving, at a first counter coupled to the first level shifter, the shifted output signal; and
determining, by the first counter, a first value representing the shifted output signal.

13. The method of claim 12 , wherein the first sensor circuit includes a ring oscillator coupled to the first digital power supply, the ring oscillator providing the output signal responsive to the value of the first local operating property, and wherein the first counter determines the first value based on a frequency of the shifted output signal received from the ring oscillator in the first sensor circuit.

14. The method of claim 12 , further comprising receiving a first value from the first counter in a shift register coupled to the first counter.

15. The method of claim 12 , further comprising:
receiving, at a ring oscillator coupled to the second digital power supply, the second supply voltage; and
assessing, at the ring oscillator, a local aging property; and
providing, from the ring oscillator, an output signal corresponding to the first counter, wherein the output signal corresponds to the local aging property.

16. The method of claim 12 , further comprising:
receiving, at a second sensor circuit, the first supply voltage from the first digital power supply, wherein the second sensor circuit produces a second output signal responsive to a value of a second local operating property of the second distal functional circuitry, and wherein the second local operating property is different from the first local operating property.

17. The method of claim 16 , further comprising:
shifting a level of the second output signal responsive to the value of the second local operating property using a second level shifter coupled to the second sensor circuit, wherein the shifted second output signal is shifted corresponding to the second supply voltage;
receiving, at a second counter coupled to the second level shifter, the shifted second output signal; and
determining, by the second counter, a second value representing the shifted second output signal.

18. An integrated circuit, comprising:
a plurality of functional circuit blocks each including functional circuitry;
a first digital power supply that provides a first supply voltage during use;
a second digital power supply, wherein the second digital power supply provides a supply voltage with a magnitude in a limited range during use; and
a plurality of sensors, wherein each of the plurality of functional circuit blocks includes at least one of the plurality of sensors implemented therein, and wherein at least one of the plurality of sensors includes:
a firs

Assignees

• Apple Inc

Inventors

• Ahmed Ramy A
• Garlepp Bruno W
• Savoj Jafar

Classifications

• G01K7/425

  Thermal management of integrated systems · CPC title

• H03K21/403 Primary

  Arrangements for storing the counting state in case of power supply interruption · CPC title

• G01K7/346

  for measuring temperature based on the time delay of a signal through a series of logical ports · CPC title

• H03K19/018521

  of complementary type, e.g. CMOS · CPC title

• H03K19/0013 Primary

  in field effect transistor circuits · CPC title