A Low-Power, Wide-Bandwidth, Three-Axis MEMS Accelerometer ASIC Using Beyond-Resonant-Frequency Sensing

• Published in: IEEE journal of solid-state circuits 2024-03, Vol.59 (3), p.774-783
• Main Authors: Lin, James, Pham, Long, Tao, Ran, Gutmann, A, Guo, Shanglin, Cywar, Adam, Spirer, Adam, Mansson, Johan, Nguyen, Khiem
• Format: Article
• Language: English
• Subjects: Accelerometers; analog-to-digital converters (ADCs); Application specific integrated circuits; Bandwidths; Capacitors; delta-sigma modulators (DSMs); equalizers (EQs); inertial sensors; micro-electromechanical system (MEMS); Microelectromechanical systems; Micromechanical devices; Resistors; Resonant frequency; Sensors; Signal paths; Switches; Three axis; Transfer functions
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2023.3344114

This article presents a 16-bit wide-bandwidth (BW) high-performance (HP) three-axis micro-electromechanical system (MEMS) accelerometer readout application-specific integrated circuit (ASIC). It is the world's first accelerometer to use beyond-resonant-frequency sensing technique to extend the BW by digitizing and equalizing the full sensor response including the MEMS sensor resonance. The readout ASIC consists of dual signal paths: three 16-bit HP signal paths to sense frequency-rich signals, such as acoustic or vibration, and one shared 12-bit low-power (LP) signal path to sense temperature and motion simultaneously. The ASIC is fabricated in 0.18- \mu \text{m} CMOS technology and is packaged with two three-axis MEMS sensors achieving a 4-kHz, 25- \mu \text{g} / \surd Hz, ±8-g accelerometer consuming 375 \mu \text{A} and an 8-kHz, 59- \mu \text{g} / \surd Hz, ±30-g accelerometer consuming 550 \mu \text{A} . The proposed technique compensates the transfer function deviation from 4.6 and 8.9 dB to less than ±0.56 and ±0.52 dB in two accelerometer prototypes.