Silicon Laboratories Inc.
Monotonicity self-testing for analog-to-digital converters

Abstract:

A method for operating an ADC includes storing a sampled input charge on a capacitance of a sample-and-hold circuit including a DAC. The sampled input charge is stored using a first reference signal coupled to the DAC and a second signal. The sampled input charge has a value based on a first digital code. The method includes converting a second digital code to an analog signal on the first node using the DAC, the sampled input charge, and the first reference signal. The second digital code is one least-significant bit different from the first digital code. The method includes generating a monotonicity indicator indicating whether an output analog signal of the DAC is monotonic in response to a transition of a digital input of the DAC from the first digital code to the second digital code based on a comparison of the analog signal to the second signal.