Patent ID: 9733268
Date: 2017-08-15
CPC Classifications: B81C,G01P

Claim:
1. A testing apparatus to determine stiction failure in MEMS devices, the apparatus comprising: a MEMS device comprising at least a first sensing electrode, at least one stopper electrode that is separate from the first sensing electrode, and a rotatable proof mass; a first front-end circuit coupled to the MEMS device, the first front-end circuit, in a stiction test mode in which the rotatable proof mass rotates toward the first sensing electrode and contacts the stopper electrode but not the first sensing electrode, detects a change in capacitance between the first sensing electrode and the rotatable proof mass to detect a stiction tendency between the rotatable proof mass and the stopper electrode, the first front-end circuit, in an acceleration reading mode, being decoupled from the MEMS device; a second front-end circuit coupled to the MEMS device, the second front-end circuit, in the acceleration reading mode, detecting a capacitance between the rotatable proof mass and the first sensing electrode; a forcing driver circuit that, in the stiction test mode, applies a bias voltage to the first sensing electrode to cause a contact between the stopper electrode and the rotatable proof mass; and a high-voltage control circuit coupled to the MEMS device, the high-voltage control circuit decoupling and coupling the first front-end circuit from the MEMS device and decoupling and coupling the forcing driver circuit from the first sensing electrode by selectively switching between the acceleration reading and stiction test modes, respectively; wherein in the stiction test mode the high-voltage control circuit couples the first front-end circuit and the forcing driver circuit to the MEMS device and decouples the second front-end circuit from the MEMS device, and in the acceleration reading mode the high-voltage control circuit decouples the first front-end circuit and the forcing driver circuit from the MEMS device and couples the second front-end circuit to the MEMS device.