A modified histogram approach for accurate self-characterization of analog-to-digital converters

A new approach for measuring the INL and DNL of an A/D Converter that uses histogram information is introduced. Unlike most existing algorithms, this method does not require the generation of accurate input signals so offers potential for use in a Built-in Self-Test (BIST) environment. Multiple inputs are presented to the device under test and the histograms obtained at the output are analyzed to characterize both the device and the nonlinear input. Preliminary simulation results for a 10-bit flash ADC suggest this approach can measure INL to the 0.5LSB level with a low spectral purity input signal that is linear to less than the 4-bit level.