A kind of high precision

low cost micro capacitive pressure measuring device is designed.This pressure measuring device uses the shell itself as a pressure sensitive components.It converts the change of pressure signal to the capacitance variable quantity through the transient decrescent capacitance conversion circuit

and change it to voltage signal that could be sampled and storaged by microcontroller through differential DC charging method.The instrument has characteristics of low power consumption

small volume

high resolution and low cost.The basic principle and the specific implementation of micro capacitive pressure measuring device are illustrated

and its feasibility is proved through comparing ANSYS software simulation results and the measured data.