New switching sequence for gradient error compensation in thermometer-decoded DAC arrays

Abstract

This paper discusses switching schemes for gradient error compensation in unary (thermometer-decoded) arrays of digital-to-analog converters (DACs). We present a new optimizing switching sequences which can compensate the gradient error of DAC's converting arrays. With the new method we can not only get the optimized bound of integral nonlinearity (INL) causing by DAC's gradient error but also substantially reduce the nonlinear noise energy during the small signal converting so as to improve the signal-to-noise ratio (SNR) of the output signal.