Large-Swing Low-Distortion High Voltage Amplifier Design for MEMS Gyroscopes

摘要

This paper presents a high-performance highvoltage (HV) amplifier with an on-chip charge pump for MEMS gyroscopes. The HV amplifier is realized by an HV operational amplifier (op-amp) and a resistance negative feedback. The HV op-amp is a single-stage differential scheme with an HV NMOS input pair and an HV PMOS current mirror. Two integrated polysilicon resistors detect the output voltage and feed it back to the negative input of the op-amp. The on-chip charge pump is the Dickson type, works at skipping mode, and provides as high as $300 mu mathrm{A}$ load current for the HV amplifier. Based on the HHGrace $0.35 mu mathrm{m}$ Bipolar-CMOS-DMOS process, the proposed HV amplifier and the high-efficiency charge pump were designed. Post-simulation results show that the charge pump can output a stable voltage of 20V with a ripple of ±320 mVp-p for the HV amplifier. The gain, bandwidth, harmonic distortion, and output swing of the HV amplifier are 6, 2.2 MHz, −40 dBc, and 12 Vp-p, respectively. The total power consumption is 7.4 mW under a 5 V supply.