Internally calibrated analog-to-digital converter
AssigneeAnalog Devices International Unlimited Company
InventorDaniel Henrik Saari
Life of this patent
Estimating the term…
Abstract
An analog-to-digital converter (ADC) system for providing a calibrated voltage measurement without an external reference voltage may include an ADC circuit, including an analog ADC input and a digital ADC output. The ADC system may also include circuitry to generate a first internal reference voltage and a second internal reference voltage. The ADC system may also include circuitry configured to provide a selected output from a number of inputs, wherein the inputs include inputs to receive (1) the first internal reference voltage, (2) the second internal reference voltage, and (3) a user-provided analog signal of interest, wherein the selected output can be connected to the analog ADC input, an external voltage measurement device, or both.
Claims20
A method for operating an analog-to-digital converter (ADC) system, the method comprising:
- receiving a measured first reference value corresponding to a first internal reference voltage of the ADC system measured by an external voltage measurement device;
- receiving a measured second reference value corresponding to a second internal reference voltage of the ADC system measured by the external voltage measurement device;
- applying the first internal reference voltage to an input of an internal ADC to generate a resulting first calibration value;
- applying the second internal reference voltage to the input of the internal ADC to generate a resulting second calibration value;
- measuring a signal value of an analog signal of interest applied to the input of the internal ADC;
- and
- providing a corrected value, corresponding to the measured signal value, using the first reference value, the second reference value, the first calibration value, the second calibration value, and the measured signal value.
An analog-to-digital converter (ADC) system for providing a calibrated voltage measurement without an external reference voltage, the ADC system comprising:
- an ADC circuit, including an analog ADC input and a digital ADC output;
- circuitry to generate a first internal reference voltage and a second internal reference voltage;
- and
- circuitry configured to provide a selected output from a number of inputs, wherein the inputs include inputs to receive (1) the first internal reference voltage, (2) the second internal reference voltage, and (3) a user-provided analog signal of interest, wherein the selected output can be connected to the analog ADC input, an external voltage measurement device, or both.
A method of operating an analog-to-digital converter (ADC) system with a factory characterization mode and an end-user operational mode, the method comprising:
- during the end-user operational mode:
- obtaining a reference data set, wherein the reference data set includes a digital representation of one or more internal reference voltages as measured by a voltage measurement device during the factory characterization mode;
- obtaining a measured signal value, wherein the measured signal value is a digital representation of an analog signal of interest obtained by applying the analog signal of interest to an input of an ADC in the ADC system;
- obtaining a calibration data set, wherein the calibration data set includes a digital representation of the one or more internal reference voltages obtained by applying the one or more internal reference voltages to the input of the ADC;
- and
- mapping the measured signal value from a curve transecting the calibration data set to a curve transecting the reference data set to obtain a corrected value.
Dependencies are inferred from the claim text.