The industry reached an inflection point where analog is getting a fresh look, but digital will not cede ground readily.
We live in an analog world dominated by digital processing, but that could change. Domain specificity, and the desire for greater levels of optimization, may provide analog compute with some significant advantages — and the possibility of a comeback. For the last four decades, the advantages of digital scaling and flexibility have pushed the dividing line between analog and digital closer to the periphery. Today, those conversions are usually done in, or very close to the sensors and actuators. Communications always has been a holdout because channels, be they wired or wireless, do not acquiesce to the demands of digital. Fig. 1: Heathkit analog computer from the 1960s. Source: Wikimedia Commons But there are several significant changes on the horizon, including: Chip scaling is slowing or stopping in an economic sense, meaning that future gains from digital scaling are no longer assured. This is one of the main drivers for domain-specific architectures. Domain specificity means that the value of flexibility has been reduced, which was a negative for analog in the past. Reticle limits mean that many systems will become multi-die, and each die does not have to be implemented in the same technology node. That may make older, cheaper nodes available for analog. AI inferencing is heavily dependent on multiply/accumulate operations, which are highly efficient in analog. Approximate computing is likely to become more prevalent. Latency is becoming a more important performance requirement. "The world is analog, so the circuits will be," says Benjamin Prautsch, group manager of advanced mixed-signal automation at Fraunhofer IIS' Engineering of Adaptive Systems Division. "There are classes of IP that benefit significantly from both digital assistance and full digital replacement. However, the benefit needs to be investigated at the system level because the conversion between analog and digital creates limits. A clever analog circuitry might outclass a medium one…