Ultrahigh-G Accelerometer Readout IC with Adaptive Gain Path for Shock Resilience

This paper proposes an accelerometer readout integrated circuit (IC) that supports micro-electromechanical systems (MEMS) piezoresistive accelerometers designed for ultrahigh-G measurements. The IC utilizes an adaptive gain path and shock detector to address circuit saturation and settling issues when shock signals are injected. This enables the use of a capacitive coupling structure that mitigates the offsets resulted from sensor mismatches. Additionally, the capacitive coupling allows to employ different supply voltages for the MEMS sensor and the IC. Thus, the IC can use a much lower supply voltage for low power consumption while the MEMS sensor can use a high supply voltage for better output sensitivity. By bypassing a gain stage for lower overall channel gain during the shock signals, the system can ensure the acquisition of accurate signal immediately after the shock signal. The IC was fabricated in 180nm CMOS technology, consuming 1.02 mW from a 1.8V supply voltage. Measurement results show a 85% and 89% enhancement in the common-mode offset and a gain error for a 1-ms shock signal when the proposed adaptive gain is used. The IC with a MEMS piezoresistive accelerometer is also validated by a 50 kG shock survival test.