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arXiv · 2508.17562

A 28nm 1.80Mb/mm2 Digital/Analog Hybrid SRAM-CIM Macro Using 2D-Weighted Capacitor Array for Complex Number Mac Operations

Shota Konno·Che-Kai Liu·Sigang Ryu·Samuel Spetalnick·Arijit Raychowdhury
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Abstract

A 28nm dense 6T-SRAM Digital(D)/Analog(A) Hybrid compute-in-memory (CIM) macro supporting complex num-ber MAC operation is presented. By introducing a 2D-weighted Capacitor Array, a hybrid configuration is adopted where digital CIM is applied only to the upper bits and ana-log CIM is applied to the rest, without the need for input DACs resulting in improved accuracy and lower area overhead. The CIM prototype macro achieves 1.80 Mb/mm2 memory density and 0.435% RMS error. Complex CIM unit outputs real and imaginary part with a single conversion to reduce latency.

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Shota Konno, Che-Kai Liu, Sigang Ryu, Samuel Spetalnick, Arijit Raychowdhury. 2025-08-25. A 28nm 1.80Mb/mm2 Digital/Analog Hybrid SRAM-CIM Macro Using 2D-Weighted Capacitor Array for Complex Number Mac Operations. https://arxiv.org/abs/2508.17562

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