Method and apparatus for closed loop control of supply and/or comparator common mode voltage in a successive approximation register analog to digital converter
A method and apparatus for controlling supply voltage for a successive approximation register analog to digital converter and comparator common mode voltage. The method comprises: measuring a successive approximation register conversion time; comparing the successive approximation register conversion time with a desired conversion time; and if necessary, performing a closed loop adjustment of at least one of the supply and/or comparator common mode voltage. The apparatus consists of a common mode voltage and regulator correction module. The common mode voltage and regulator correction module includes a phase frequency detector, a charge pump and may include a transconductance cell.
1. A method for controlling supply voltage for a successive approximation register (SAR) analog to digital converter (ADC) comparator common moved voltage, comprising:
measuring a SAR conversion time;
comparing the SAR conversion time to a desired conversion time; and
adjusting in closed loop fashion at least one of a supply and comparator common mode voltage.
2. The method of claim 1 , wherein both the supply and the comparator common mode voltages are adjusted.
3. The method of claim 1 , wherein the supply voltage is adjusted.
4. The method of claim 1 , wherein the comparator common mode voltage is adjusted.
5. An apparatus for controlling supply voltage for a successive approximation register (SAR) analog to digital converter (ADC) and comparator common mode voltage comprising:
a common mode voltage and regulator correction module, electrically connected to a SAR ADC module.
6. The apparatus of claim 5 wherein the common mode voltage and regulator correction module includes a phase frequency detector.
7. The apparatus of claim 6 , wherein the common mode voltage and regulator correction module includes a charge pump.
8. The apparatus of claim 7 , wherein the common mode voltage and regulator correction module includes a transconductance cell.
9. An apparatus for controlling supply voltage for a successive approximation register (SAR) analog to digital converter (ADC), comprising:
means for measuring SAR conversion time;
means for comparing the SAR conversion time to a desired conversion time; and
means for adjusting in closed loop fashion at least one of a supply and comparator common mode voltage.
10. The apparatus of claim 9 wherein the means for adjusting in closed loop fashion at least one of a supply and comparator common mode voltage includes means for adjusting both the supply and comparator common mode voltages.
11. The apparatus of claim 9 wherein the means for adjusting in closed loop fashion at least one of a supply and comparator common mode voltage includes means for adjusting the supply voltage.
12. The apparatus of claim 9 wherein the means for adjusting in closed loop fashion at least one of a supply and comparator common mode voltage includes means for adjusting the comparator common mode voltage.
13. A non-transitory computer-readable medium, comprising instructions, which when executed by a processor cause the processor to perform the steps of:
measuring a SAR conversion time;
comparing the SAR conversion time to a desired conversion time; and
adjusting in closed loop fashion at least one of a supply and comparator common mode voltage.
14. The non-transitory computer-readable medium of claim 13 , further comprising instructions for adjusting in closed loop fashion both the supply and the comparator common mode voltage.
15. The non-transitory computer-readable medium of claim 13 , further comprising instructions for adjusting in closed loop fashion the supply voltage.
16. The non-transitory computer-readable medium of claim 13 , further comprising instructions for adjusting in closed loop fashion the comparator common mode voltage.