公开(公告)号：US20190181874A1

公开(公告)日：2019-06-13

申请号：US16266470

申请日：2019-02-04

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Steven John LOVELESS ,  Yuguo WANG ,  Tathagata CHATTERJEE ,  Robert Stanley GRONDALSKI

IPC: H03M1/10 ,  H03K21/08 ,  G01R27/26 ,  H03K5/24

Abstract: An analog-to-digital converter (ADC) comprising successive approximation circuitry, a capacitive analog-to-digital converter (CDAC), and capacitor mismatch measurement circuitry. The successive approximation circuitry is configured to control conversion of an analog signal to a digital value. The CDAC is coupled to the successive approximation circuitry. The CDAC includes a plurality of capacitors. The capacitor mismatch measurement circuitry is coupled to the CDAC. The capacitor mismatch measurement circuitry includes a first oscillator circuit, a second oscillator circuit, and counter circuitry. The first oscillator circuit is configured to oscillate at a frequency determined by a capacitance of one of the capacitors. The second oscillator circuit is configured to generate a predetermined time interval. The counter circuitry is configured to count a number of cycles of oscillation of the first oscillator in the predetermined time interval.