Low power, low noise micropipelined flash A-D converter

Metastability in the comparators of high speed synchronous flash A-D converters is a source of noise in the output. Pipelining can reduce metastability errors but can consume significant power in synchronous systems, and techniques have been described which aim to reduce the power, but can lead to nonlinearity. It is shown that power can also be reduced without loss of linearity by asynchronous micropipelining techniques which allow the comparison times to vary without a high probability of metastability noise. Other advantages resulting from asynchronous internal timing include a reduction in clock noise, and improved tolerance to process and interconnect delays