Compensation controller and MEMS accelerometer closed-loop servo special integrated circuit

Abstract

The invention discloses a compensation controller. The compensation controller comprises an operational amplifier, a first resistor, a second resistor, a first capacitor, a second capacitor, a first switch, a second switch and a third switch; the compensation input end is connected with the reverse input end of the operational amplifier after being connected with the first resistor; the positive input end of the operational amplifier is grounded, and the output end is connected with the feedback output end; the first capacitor is connected with the compensation input end and the reverse inputend of the operational amplifier; the first switch and the first capacitor are connected in series; the second resistor, the third switch the second capacitor are connected in series, and then the integral end is connected with the output end of the operational amplifier, and the other end is connected with the reverse input end thereof; and the third switch and the second capacitor are connectedin series and then are connected with the second switch in parallel. The compensation controller is used for an accelerometer closed-loop control system, and the compensation modes can be changed according to different sensitive structures of the accelerometers, so that the system performance is improved, and the system stability is enhanced.

Description

technical field [0001] The invention belongs to the field of integrated circuit design, specifically relates to a compensation controller, and also relates to a MEMS accelerometer closed-loop servo special integrated circuit using the compensation controller. Background technique [0002] Micro Electromechanical System (MEMS for short) is a multidisciplinary interdisciplinary technology developed on the basis of microelectronics and micromechanical technology. It includes micro sensors, micro actuators, signal processing and control circuits and communication interfaces, etc. The sensing device of the MEMS accelerometer is usually processed with a process similar to that of microelectronics, so it is easy to integrate with the microelectronic circuit, and its readout circuit is usually designed with an integrated circuit, so the signal can be amplified and the noise can be optimized. [0003] The existing MEMS capacitive accelerometer servo circuit is divided into a closed-...

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Problems solved by technology

[0004] MEMS accelerometer is a second-order system. In order to achieve stable closed-loop control, it needs the cooperation of closed-loop servo ASICs to achieve high performance indicators; the previous ASICs are fixed, so they are limited in practical applications. limit

Moreover, there is uncertain interference in the work of the micro accelerometer, and with the increase of the service time of the micro accelerometer, the structural performance parameters and circuit parameters of the sensor will change slightly

These factors will bring errors to the sensor output, and may also cause instability in the closed-loop system. Therefore, for a second-order system such as a micro-accelerometer, direct feedback without any controller cannot meet the performance requirements of the circuit. It is necessary to design an excellent compensation controller to adjust the phase of the system and improve the stability of the system

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