Synchronous and asynchronous A-D conversion

Analog-digital (A-D) converters with a fixed conversion time are subject to errors due to metastability, It is shown that an asynchronous converter in which the conversion time is not bounded is faster, on average, than the s ynchronous design. Real-time applications require the data to be produced w ithin a fixed time, and failures may occur with the long conversion times t hat can arise with fully asynchronous converters. For these applications, w e show that an internally asynchronous bounded time converter is both faste r and more reliable than a synchronous converter.