Gated ring oscillator linearization

Patent metadata

Field	Value
Publication number	US-11762340-B2
Application number	US-202117390291-A
Country	US
Kind code	B2
Filing date	Jul 30, 2021
Priority date	Jul 30, 2021
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

Aspects of the disclosure provide for an apparatus comprising a time-to-digital converter (TDC) and a processor coupled to the TDC. In some examples, the TDC may be configured to receive a signal and generate a measurement result indicating a time between start and stop events of the signal. The processor may be configured to receive the measurement result, compare the measurement result to a target value, and determine a non-linearity model configured to correct a variance of the measurement result from the target value.

First claim

What is claimed is:

1. An apparatus comprising:
a time-to-digital converter (TDC) configured to:
receive a signal; and
generate a measurement result indicating a time between start and stop events of the signal; and

a processor coupled to the TDC and configured to:
receive the measurement result;
compare the measurement result to a target value; and
determine a non-linearity model configured to correct a variance of the measurement result from the target value.

2. The apparatus of claim 1 , wherein the TDC is a gated ring oscillator (GRO) based TDC.

3. The apparatus of claim 1 , wherein the non-linearity model is implemented as a look-up table.

4. The apparatus of claim 1 , wherein the non-linearity model is implemented as a polynomial function.

5. The apparatus of claim 1 , further comprising a multiplexer having a first input configured to receive a calibration signal, a second input configured to receive an operating mode signal, and an output coupled to the TDC, the multiplexer configured to:
receive a control signal;
provide the calibration signal as the signal responsive to the control signal having an asserted value; and
provide the operating mode signal as the signal responsive to the control signal having a de-asserted value.

6. The apparatus of claim 1 ,
wherein the TDC is configured to:
receive a second signal; and
generate a second measurement result indicating a time between start and stop events of the second signal; and

wherein the processor is configured to:
receive the second measurement result; and
process the second measurement result according to the non-linearity model to provide a corrected result, wherein the corrected result compensates for non-linearities in the second measurement result.

7. The apparatus of claim 1 , wherein the signal includes multiple pulses having a different duration determined as a multiple of a period of a clock signal.

8. A method, comprising:
receiving, by a gated ring oscillator (GRO) based time-to-digital converter (TDC), a calibration signal;
measuring, by the GRO based TDC, the calibration signal to provide a measurement result, the measurement result including variance from a target value; and
processing the measurement result to determine a non-linearity model, the non-linearity model defining the variance of the measurement result from the target value.

9. The method of claim 8 , wherein the target value is a value indicative of a linear response.

10. The method of claim 8 , wherein the non-linearity model is implemented as a look-up table.

11. The method of claim 8 , wherein the non-linearity model is implemented as a polynomial function.

12. The method of claim 8 , further comprising:
receiving an operating mode signal;
measuring the operating mode signal to provide a second measurement result, the second measurement result including variance from a target value; and
processing the second measurement result according to the non-linearity model to compensate for the variance in the second measurement result from the target value.

13. The method of claim 12 , further comprising a processor determining the non-linearity model and processing the second measurement result according to the non-linearity model.

14. The method of claim 8 , wherein processing the measurement result to determine the non-linearity model comprises comparing the measurement result to the target value to determine the variance of the measurement result from the target value.

15. A method, comprising:
receiving an operating mode signal;
measuring, by a gated ring oscillator (GRO) based time-to-digital converter (TDC), the operating mode signal to provide a measurement result, the measurement result including variance from a target value; and
processing the measurement result according to a non-linearity model defining the variance of the measurement result from the target value to provide a corrected result.

16. The method of claim 15 , wherein the target value is a value indicative of a linear response.

17. The method of claim 15 , wherein the corrected result includes less variance from the target value than does the measurement result.

18. The method of claim 15 , further comprising:
receiving a calibration signal;
measuring the calibration signal to provide a second measurement result, the second measurement result including variance from the target value; and
processing the second measurement result to determine the non-linearity model, the non-linearity model defining the variance of the second measurement result from the target value.

19. The method of claim 18 , wherein the calibration signal is received and measured by a GRO based TDC.

20. The method of claim 18 , wherein processing the measurement result to determine the non-linearity model comprises comparing the measurement result to the target value to determine the variance of the measurement result from the target value.

Assignees

• Texas Instruments Inc

Inventors

• Moe Marius
• Aaberge Tarjei
• Patel Bijit

Classifications

• H03K3/0315 Primary

  Ring oscillators · CPC title

• G04F10/005 Primary

  Time-to-digital converters [TDC] (analog-to-digital converters with intermediate conversion to time or phase H03M1/50, H03M1/60) · CPC title