A 132dBΩ 427MHz transimpedance amplifier for driving MEMS resonators

This paper presents a multi-stage transimpedance amplifier (TIA) design for driving MEMS resonators, specifically targeting a MEMS resonator with 20MHz resonance frequency. The multi-stage architecture comprises: 1) A modified Regulated Cascode (RGC) input stage that reduces input impedance and extends system bandwidth; 2) A Cherry Hooper intermediate stage with temperature compensation ports to enhance gain while ensuring stable operation across wide temperature ranges; 3) A common-source output stage achieving essential phase inversion through minimal structure to meet oscillation initiation requirements. Implemented in SMIC 0.18μm CMOS process, the TIA demonstrates 132dBΩ gain, 427MHz bandwidth, and low input-referred noise current of 2.85pA/√Hz. Experimental results show successful excitation of MEMS resonator with 20.18MHz stable oscillation at 2.6V amplitude and 45μs startup time, exhibiting phase noise of -124.16dBc/Hz @ 100kHz offset. This design provides an effective implementation reference for high-frequency MEMS resonator driving circuits.