An architecture for first-order tunable mismatch shaping in oversampled data converters

Mismatch shaping is a commonly used technique for shaping the noise created by mismatch errors in over-sampled digital-to-analog converters. Mismatch shaping techniques reported thus far operate with the signal band located at a fixed frequency. This paper presents a simple architecture for arbitrarily tuning the center frequency of a first-order mismatch shaping transfer function. Details of hardware implementation are provided, and the hardware complexity is analyzed. Results from simulations show a consistently improved signal-to-noise ratio at tuning frequency settings across the entire Nyquist bandwidth.