A 55nm Low-Noise Super-Source-Follower Preamplifier for MEMS Microphones

Abstract

In this paper a low-power, low-noise interface for Micro Electro-Mechanical System (MEMS) silicon microphones built in a 55 nm MOSFET technology is presented. The designed interface is made up by a pseudo-differential structure, based on two single-ended Super-Source-Followers with PMOS input device, to reduce Flicker noise contribution that would affect low frequency applications. The challenge of this design regards the implementation in 55 nm of high performance analog cells. The device performs output integrated noise in the [20 Hz 20 kHz] audio band of about -110 dBV(A), with a total power consumption of 270 $\mu{\mathrm W}$ from a 1.5 V voltage supply. Acoustic Overload Point (AOP) reaches a mean value of 130 dBspl.