Integrated Analog Computers as Domain-Specific Accelerators: A Tutorial Review

Recent innovations in devices, circuits, and systems have resulted in the widespread use of parallel and in-memory architectures for energy-efficient computing. However, the choice of signal representation within these architectures has received less attention. Nevertheless, computing using analog variables is known to be fundamentally more resource-efficient for low-and moderate-precision operations, making it of interest for applications, such as inference and real-time control, where high precision is not a requirement. However, well-known difficulties with scalability, programambility, and memory access have im-peded the realization of integrated analog computers (ACs) that can utilize these fundamental advantages. This paper provides a tutorial-style review of state-of-the-art integrated ACs and their advantages, including ultra-low latency and high energy-efficiency, for solving selected problems where clocked digital architectures are not resource-efficient.