Methods and apparatus for calibrating a regulated charge sharing analog-to-digital converter (ADC)
AssigneeMovellus Circuits, Inc.
InventorsJeffrey Alan Fredenburg, Yuxiang Mu, Noman Hai
Life of this patent
Estimating the term…
Abstract
A method of operation in an analog-to-digital converter (ADC) includes performing a calibration operation. The calibration operation includes sampling an input analog reference voltage. A sequence of charge sharing transfers is then performed with a charge sharing regulator to transfer an actual amount of charge between a charge source and a charge load based on the input analog reference voltage. The transferred actual amount of charge is compared to a reference charge value corresponding to the reference voltage. A control input to the charge sharing regulator is adjusted to correspondingly adjust charge sharing of a subsequent amount of charge based on the comparing.
Claims20
A method of operation in an analog-to-digital converter (ADC), the method comprising:
- performing a calibration operation including
- sampling an input analog reference voltage;
- performing a sequence of charge sharing transfers with a charge sharing regulator to transfer an actual amount of charge between a charge source and a charge load based on the input analog reference voltage;
- comparing the transferred actual amount of charge to a reference charge value corresponding to the reference voltage;
- and
- adjusting a control input to the charge sharing regulator to correspondingly adjust charge sharing of a subsequent amount of charge based on the comparing.
A method of operation in an integrated circuit (IC) chip, the method comprising:
- initiating an analog-to-digital converter (ADC) conversion operation for the IC chip during a conversion time interval;
- and
- initiating an ADC calibration operation for the IC chip during a calibration time interval, wherein an output value of an ADC and a corresponding input value exhibits an operating ADC transfer function, the performing of the ADC calibration operation including
- sampling an input analog reference voltage;
- performing a sequence of charge sharing transfers with a charge sharing regulator to transfer an actual amount of charge between a charge source and a charge load based on the input analog reference voltage;
- comparing the transferred actual amount of charge to a reference charge value corresponding to the reference voltage;
- and
- adjusting a control input to the charge sharing regulator based on the comparing, the adjusting of the control input to change the operating ADC transfer function.
An integrated circuit (IC) chip, comprising:
- an analog-to-digital converter (ADC) circuit including a regulated charge sharing circuit to regulate charge sharing transfers involved in converting an input voltage to a digital word, the ADC circuit exhibiting an actual ADC transfer function based on a control input of the regulated charge sharing circuit;
- and
- calibration circuitry to adjust the control input of the regulated charge sharing circuit by an adjustment value, the adjustment value based on a comparison of an actual amount of transferred charge to a reference charge value.
Dependencies are inferred from the claim text.