A PWM-DAC for Analog In-Memory Computing in Mixed-Signal Accelerators

This paper proposes the design of a Pulse Width Modulation Digital to Analog Converter (PWM-DAC) for Analog in-Memory Computing. The converter generates voltage pulses, with pulse-width proportional to the 7-bit digital input, in sign-magnitude format. The circuit is designed in a 22-nm FD-SOI technology, with a layout tailored for the severe pitch and area requirements of the memory array for AiMC. The circuit achieves sub-500 fJ/conversion energy consumption, supplied at 0.85 V. The converter obtains an Integral-Non-Linearity (INL) and Differential-Non-Linearity (DNL), normalized at the LSB, lower than 7% and 12%, respectively.