High-voltage reset mems microphone network and method of detecting defects thereof

Abstract

A method of detecting defects in a high impedance network of a MEMs microphone sensor interface circuit. The method includes adding a high-voltage reset switch to a high-voltage high impedance network, closing the high-voltage reset switch during a start-up phase of the MEMs microphone sensor interface circuit, simultaneously closing a low-voltage reset switch of a low-voltage high impedance network during the start-up phase, simultaneously opening the high-voltage reset switch and the low-voltage reset switch at the end of the start-up phase, and detecting a defect in the high-voltage high impedance network or the low-voltage high impedance network immediately after opening the high-voltage reset switch and the low-voltage reset switch.

What is claimed is: 
     
         1 . A method of detecting defects in a high impedance network of a MEMs microphone sensor interface circuit, the method comprising:
 closing a high-voltage reset switch during a start-up phase of the MEMs microphone sensor interface circuit;   closing a low-voltage reset switch during the start-up phase;   simultaneously opening the high-voltage reset switch and the low-voltage reset switch at the end of the start-up phase; and   detecting a defect in a high-voltage high impedance network or a low-voltage high impedance network immediately after opening the high-voltage reset switch and the low-voltage reset switch.   
     
     
         2 . The method of  claim 1 , wherein the defect is a leakage current between a bias node of the MEMs microphone sensor interface circuit and ground. 
     
     
         3 . The method of  claim 1 , wherein the defect is a leakage current between a bias node of the MEMs microphone sensor interface circuit and a sense node of the MEMs microphone sensor interface circuit. 
     
     
         4 . The method of  claim 1 , wherein the defect is caused particles, surface contamination or bulk material defects. 
     
     
         5 . The method of  claim 1 , wherein the defect is a leakage current through one or more diodes of anti-parallel diodes of the high-voltage high impedance network or the low-voltage high impedance network. 
     
     
         6 . A high-voltage reset MEMs microphone sensor interface circuit, the circuit comprising:
 a high-voltage reset switch coupled between a charge pump and a bias node of a MEMS microphone sensor interface circuit;   a low-voltage reset switch coupled between ground and a sense nod of the MEMS microphone sensor interface circuit;   wherein the low-voltage reset switch and the high-voltage reset switch are closed during a start-up phase of the MEMs microphone sensor interface circuit and simultaneously opened at an end of the start-up phase.   
     
     
         7 . The high-voltage reset MEMs microphone sensor interface circuit of  claim 6 , wherein a defect in a low-voltage high impedance network or a high-voltage high impedance network is detected immediately after the low-voltage reset switch and the high-voltage reset switch are opened. 
     
     
         8 . The high-voltage reset MEMs microphone sensor interface circuit of  claim 7 , wherein the defect is a leakage current between the bias node of the MEMs microphone sensor interface circuit and ground. 
     
     
         9 . The high-voltage reset MEMs microphone sensor interface circuit of  claim 7 , wherein the defect is a leakage current between the bias node of the MEMs microphone sensor interface circuit and the sense node of the MEMs microphone sensor interface circuit. 
     
     
         10 . The high-voltage reset MEMs microphone sensor interface circuit of  claim 7 , wherein the defect is caused particles, surface contamination or bulk material defects. 
     
     
         11 . The high-voltage reset MEMs microphone sensor interface circuit of  claim 7 , wherein the defect is a leakage current through one or more diodes of anti-parallel diodes of the high-voltage high impedance network or the low-voltage high impedance network.