Pipelined multi-bit oversampled digital to analog converters with capacitor averaging

A combination of pipelined architecture and the dynamic element matching technique is applied to multibit oversampled D/A (digital-to-analog) converters. The approach translates the harmonic distortion components of the nonideal internal DAC (digital-to-analog converter) of the oversampled D/A converter to high-frequency components, which can then be filtered out by the analog low-pass filter for anti-imaging. Computer simulations have confirmed that, with this approach, a third-order oversampled D/A converter employing a 3-b quantizer, a 3-b pipelined internal DAC with a random mismatch of 0.1%, can achieve a 94-dB dynamic range with an oversampling ratio of 64, while eliminating the harmonic distortion.<
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