Charge pump device on basis of MEMS (Micro Electro Mechanical System) microphone bias circuit

Abstract

The invention discloses a charge pump device on the basis of a MEMS (Micro Electro Mechanical System) microphone bias circuit. The charge pump device comprises an oscillator, a reference voltage source, a clock amplitude doubling circuit, a Dickson charge pump, a low pass filter and the like. The oscillator is used for providing a two-phase non-overlapping clock with the duty cycle of 50 percent and regulating the amplitude of a two-phase non-overlapping clock signal into two times of the amplitude of a reference voltage. According to the invention, a reference voltage and clock amplitude defining circuit is added and can be used for implementing the stable high voltage output; and due to the adoption of a clock amplitude doubling technology, the number of stages of a diode-capacitance voltage unit is reduced by at least four stages, the area of a core circuit of the charge pump is at least shortened by 21 percent, the power consumption is at least reduced by 40 percent and the conversion efficiency is improved by nearly once.

Description

technical field [0001] The invention relates to integrated circuit technology, in particular to the charge pump design of a microphone bias circuit. Background technique [0002] Since J.F. Dickson first proposed the integrated charge pump circuit structure in the chip in 1976, the Dickson charge pump has gradually become the most commonly used DC-DC boost circuit in DRAM, EEPROM and flash memory devices. Due to the loss of the threshold voltage of the MOS tube in the charge pump, the Dickson charge pump often cannot achieve the ideal high output voltage at a low power supply voltage, the circuit overhead is huge, and the conversion efficiency is low. Aiming at these problems, many solutions have been proposed at home and abroad, such as static charge transfer switch technology, PMOS instead of NMOS switch to compensate body effect technology, etc. In the design of a charge pump for biasing a MEMS microphone, some important factors are involved: [0003] (1) Low power cons...

AI Technical Summary

Problems solved by technology

Due to the loss of the threshold voltage of the MOS tube in the charge pump, the Dickson charge pump often cannot achieve the ideal high output voltage at a low power supply voltage, the circuit overhead is huge, and the conversion efficiency is low

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