Granted Patent B2

US 7,957,924 · App. 12/118,217 · Granted Jun 7, 2011

Abstract

Claims (35)

1. A method comprising:

receiving, at a comparator, a first intermediate signal that is at least partially based upon a first reference signal;

receiving, at the comparator, a second intermediate signal that is a time-shifted version of the first intermediate signal;

generating, at the comparator, an output signal that is based upon the difference between the first intermediate signal and the second intermediate signal;

determining, at a processor, an anticipated differential change in the output signal, the anticipated differential change to occur based upon a transition in the first reference signal;

measuring, at the processor, a realized differential change in the output signal, the realized differential change occurring based upon a transition in the first reference signal; and

comparing, at the processor, the realized differential change in the output signal to the anticipated differential change in the output signal to determine a nonlinearity indicator.

2. The method of claim 1 wherein the first reference signal is a first digital reference signal.

3. The method of claim 2 wherein the first digital reference signal is provided to a device under test such that the device under test generates the first intermediate signal.

4. The method of claim 3 wherein the device under test includes a digital-to-analog converter.

5. The method of claim 1 wherein the first reference signal is a first analog reference signal.

6. The method of claim 5 wherein the first analog reference signal is provided to a device under test such that the device under test generates the first intermediate signal.

7. The method of claim 6 wherein the device under test includes an amplifier.

8. A circuit configured to perform operations comprising:

a comparator configured to receive a first intermediate signal that is at least partially based upon a first reference signal, the comparator further configured to receive a second intermediate signal that is a time-shifted version of the first intermediate signal, the comparator being further configured to generate an output signal that is based upon the difference between the first intermediate signal and the second intermediate signal; and

a processor configured to determine an anticipated differential change in the output signal, the anticipated differential change to occur based upon a transition in the first reference signal, the processor further configured to measure a realized differential change in the output signal, the realized differential change occurring based upon a transition in the first reference signal, the processor being further configured to compare the realized differential change in the output signal to the anticipated differential change in the output signal to determine a nonlinearity indicator.

9. The circuit of claim 8 wherein the first reference signal is a first digital reference signal.

10. The circuit of claim 9 wherein the first digital reference signal is provided to a device under test such that the device under test generates the first intermediate signal.

11. The circuit of claim 10 wherein the device under test includes a digital-to-analog converter.

12. The circuit of claim 8 wherein the first reference signal is a first analog reference signal.

13. The circuit of claim 12 wherein the first analog reference signal is provided to a device under test such that the device under test generates the first intermediate signal.

14. The circuit of claim 13 wherein the device under test includes an amplifier.

15. A computer program product residing on a non-transitory computer readable medium having a plurality of instructions stored thereon which, when executed by a processor, cause the processor to perform operations comprising:

receiving, at a comparator, a first intermediate signal that is at least partially based upon a first reference signal;

receiving, at a comparator, a second intermediate signal that is a time-shifted version of the first intermediate signal;

generating, at a comparator, an output signal that is based upon the difference between the first intermediate signal and the second intermediate signal;

determining, at a processor, an anticipated differential change in the output signal, the anticipated differential change to occur based upon a transition in the first reference signal;

measuring, at a processor, a realized differential change in the output signal, the realized differential change occurring based upon a transition in the first reference signal; and

comparing, at a processor, the realized differential change in the output signal to the anticipated differential change in the output signal to determine a nonlinearity indicator.

16. The computer program product of claim 15 wherein the first reference signal is a first digital reference signal.

17. The computer program product of claim 16 wherein the first digital reference signal is provided to a device under test such that the device under test generates the first intermediate signal.

18. The computer program product of claim 17 wherein the device under test includes a digital-to-analog converter.

19. The computer program product of claim 15 wherein the first reference signal is a first analog reference signal.

20. The computer program product of claim 19 wherein the first analog reference signal is provided to a device under test such that the device under test generates the first intermediate signal.

21. The computer program product of claim 20 wherein the device under test includes an amplifier.

Assignments (10)