BACKGROUND DAC CALIBRATION FOR PIPELINE ADC

摘要

A circuit includes a track and hold (T/H) block to track an analog input signal during a track phase and to hold the analog input signal during a hold phase. A pipelined converter stage includes an analog to digital converter (ADC) receives the analog input signal from the T/H block and generates a digital output signal corresponding to the analog input signal. A digital to analog converter (DAC) element in the pipelined converter stage receives the digital output signal from the ADC and generates a current output signal representing an analog value for a portion of the analog input signal. A detector monitors the current output signal of the DAC element with respect to a predetermined reference current during the track phase and generates a trim signal if the current output signal is different from the predetermined reference current.

主权项

1. A circuit comprising:
a track and hold (T/H) block to track an analog input signal during a track phase and to hold the analog input signal during a hold phase; a pipelined converter stage that includes an analog to digital converter (ADC) to receive the analog input signal from the T/H block and to generate a digital output signal corresponding to the analog input signal; a digital to analog converter (DAC) element in the pipelined converter stage to receive the digital output signal from the ADC and to generate a current output signal representing an analog value for a portion of the analog input signal; a detector to monitor the current output signal of the DAC element with respect to a predetermined reference current during the track phase and to generate a trim signal if the current output signal is different from the predetermined reference current; and a calibration block that adjusts the current output signal of the DAC element based on the trim signal from the detector.