An S/H interpolator for oversampling D/A converters

A novel S/H interpolator for oversampling converters is proposed where the filter coefficients are linearly combined to form the symmetric terms. It is verified that the hardware implementation is efficient due to the decreased multiplier rate and compact digital circuits. These lead to a decrease of the coupled noise, so that the performance of the analog front-end circuits in oversampling D/A (digital-to-analog) converters is not degraded. The multiplier rate is only half of that in the polyphase structure, and the number of the delay elements remains the same. Due to the lower multiplier rate, smaller chip size, and smaller transient noise, the proposed new interpolation FIR (finite impulse response) filter is more suitable in the applications of dual-channel audio-band D/A converters