Methods and apparatus to estimate analog to digital converter (ADC) error

An apparatus comprising:

• programmable circuitry;
• a first analog to digital converter (ADC) having a first input terminal connected to the programmable circuitry and a second input connected to a voltage source;
• and
• a second ADC having a first terminal connected to the programmable circuitry and a second input connected to the voltage source;
• wherein the programmable circuitry is configured to:
• determine a first output voltage from the first ADC responsive to the first ADC and a second ADC both receiving a first input voltage;
• determine a first output voltage from the second ADC responsive to the first ADC and a second ADC both receiving the first input voltage;
• determine a second output voltage from the first ADC responsive to the first ADC receiving a second input voltage and the second ADC receiving the first input voltage;
• and
• determine an error value for the first ADC based on:
• (a) a difference between the first output voltage from the first ADC and the first output voltage from the second ADC, and (b) a difference between the first output voltage from the first ADC and the second output voltage from the first ADC.

A method comprising:

• determining, with programmable circuitry, a first output voltage from a first analog to digital converter (ADC) responsive to the first ADC and a second ADC both receiving a first input voltage;
• determining, with the programmable circuitry, a first output voltage from a second ADC responsive to the first ADC and a second ADC both receiving the first input voltage;
• determining, with the programmable circuitry, a second output voltage from the first ADC responsive to the first ADC receiving a second input voltage and the second ADC receiving the first input voltage;
• and
• determining, with the programmable circuitry, an error value for the first ADC based on:
• (a) a difference between the first output voltage from the first ADC and the first output voltage from the second ADC, and (b) a difference between the first output voltage from the first ADC and the second output voltage from the first ADC.