Analog-to-digital converter-embedded fixed-phase variable gain amplifier stages for dual monitoring paths

1. A delta-sigma modulator comprising:

a loop filter;

a quantizer;

an input gain element having a programmable input gain and coupled between an input of the delta-sigma modulator and an input of the loop filter;

a feedforward gain element having a programmable feedforward gain and coupled between the input of the delta-sigma modulator and an output of the loop filter; and

a quantizer gain element having a quantizer gain and coupled between the output of the loop filter and an input of the quantizer;

wherein:

the programmable input gain is controlled in order to control a variable gain of the delta-sigma modulator; and

the programmable feedforward gain is controlled to be equal to the ratio of the programmable input gain and the quantizer gain such that the delta-sigma modulator has a fixed phase response.

2. The delta-sigma modulator of claim 1 , wherein the quantizer gain is fixed.

3. The delta-sigma modulator of claim 1 , wherein:

the input of the loop filter is coupled to an output of the quantizer; and

a feedback gain from the output of the quantizer to the input of the loop filter is one (1).

4. A method for controlling a fixed-phase gain amplifier embedded in an analog-to-digital converter, comprising:

controlling an input gain element having a programmable input gain and coupled between an input of a delta-sigma modulator and an input of a loop filter of the delta-sigma modulator in order to control a variable gain of the delta-sigma modulator; and

controlling a feedforward gain element having a programmable feedforward gain and coupled between the input of the delta-sigma modulator and an output of the loop filter to be equal to the ratio of the programmable input gain and a quantizer gain of a quantizer gain element coupled between the output of the loop filter and an input of a quantizer of the delta-sigma modulator, such that the delta-sigma modulator has a fixed phase response.

5. The method of claim 4 , wherein the quantizer gain is fixed.

6. The method of claim 4 , wherein:

the input of the loop filter is coupled to an output of the quantizer; and

a feedback gain from the output of the quantizer to the input of the loop filter is one (1).

7. A controller for controlling a fixed-phase gain amplifier embedded in an analog-to-digital converter, comprising:

a first output for controlling an input gain element having a programmable input gain and coupled between an input of a delta-sigma modulator and an input of a loop filter of the delta-sigma modulator in order to control a variable gain of the delta-sigma modulator;

a second output for controlling a feedforward gain element having a programmable feedforward gain and coupled between the input of the delta-sigma modulator and an output of the loop filter; and

logic for controlling the feedforward gain element to be equal to the ratio of the programmable input gain and a quantizer gain of a quantizer gain element coupled between the output of the loop filter and an input of a quantizer of the delta-sigma modulator, such that the delta-sigma modulator has a fixed phase response.

8. The method of claim 7 , wherein the quantizer gain is fixed.

9. The method of claim 7 , wherein:

the input of the loop filter is coupled to an output of the quantizer; and

a feedback gain from the output of the quantizer to the input of the loop filter is one (1).

10. A system for measuring a plurality of physical quantities associated with an electrical component, the system comprising a plurality of sensing paths comprising:

a first sensing path for sensing a first physical quantity associated with the electrical component; and

a second sensing path for sensing a second physical quantity associated with the electrical component;

wherein each of the first sensing path and the second sensing path respectively comprise a respective delta-sigma modulator that comprises:

a loop filter;

a quantizer;

an input gain element having a programmable input gain and coupled between an input of the delta-sigma modulator and an input of the loop filter;

a feedforward gain element having a programmable feedforward gain and coupled between the input of the delta-sigma modulator and an output of the loop filter; and

a quantizer gain element having a quantizer gain and coupled between the output of the loop filter and an input of the quantizer;

wherein:

the programmable input gain is controlled in order to control a variable gain of the delta-sigma modulator; and

the programmable feedforward gain is controlled to be equal to the ratio of the programmable input gain and the quantizer gain such that the delta-sigma modulator has a fixed phase response.

11. The system of claim 10 , wherein the quantizer gain for each respective delta-sigma modulator is fixed.

12. The system of claim 10 , wherein in each respective delta-sigma modulator:

the input of the loop filter is coupled to an output of the quantizer; and

a feedback gain from the output of the quantizer to the input of the loop filter is one (1).

13. The system of claim 10 , wherein:

the first physical quantity is a voltage associated with the electrical component; and

the second physical quantity is a current associated with the electrical component.

14. The system of claim 10 , wherein the electrical component comprises an electromagnetic transducer.

15. A device comprising:

an electrical component;

a driver configured to drive a waveform to the electrical component; and

a measurement subsystem for measuring a plurality of physical quantities associated with the electrical component, the measurement subsystem comprising a plurality of sensing paths comprising:

a first sensing path for sensing a first physical quantity associated with the electrical component; and

a second sensing path for sensing a second physical quantity associated with the electrical component;

wherein each of the first sensing path and the second sensing path respectively comprise a respective delta-sigma modulator that comprises:

a loop filter;

a quantizer;

an input gain element having a programmable input gain and coupled between an input of the delta-sigma modulator and an input of the loop filter;

a feedforward gain element having a programmable feedforward gain and coupled between the input of the delta-sigma modulator and an output of the loop filter; and

a quantizer gain element having a quantizer gain and coupled between the output of the loop filter and an input of the quantizer; wherein:

the programmable input gain is controlled in order to control a variable gain of the delta-sigma modulator; and

the programmable feedforward gain is controlled to be equal to the ratio of the programmable input gain and the quantizer gain such that the delta-sigma modulator has a fixed phase response.

16. The device of claim 15 , wherein the quantizer gain for each respective delta-sigma modulator is fixed.

17. The device of claim 15 , wherein in each respective delta-sigma modulator:

the input of the loop filter is coupled to an output of the quantizer; and

a feedback gain from the output of the quantizer to the input of the loop filter is one (1).

18. The device of claim 15 , wherein:

the first physical quantity is a voltage associated with the electrical component; and

the second physical quantity is a current associated with the electrical component.

19. The device of claim 15 , wherein the electrical component comprises an electromagnetic transducer.

20. The device of claim 15 , further comprising a control system configured to control the waveform based on the plurality of physical quantities.