Study And Analysis Of The Infrared Sensor Design In CMOS Process

The application of the infrared sensor is very extensive, no matter the guided missile guide equipment correlated with the national defence, and measuring the age of the building correlated with the commerce, even in the medical diagnosis system correlated with the people's livelihood. This thesis proposes new-type thermo-electricity infrared sensor utilizing technology of mems(Micro-Electro-Mechanical Systems) in a standard TSMC 0. 35um CMOS process. It adopt electric thermocouple suspended structure which hide in the membrane absorbing infrared ray. So its fill factor and responsively is high, but noise equivalent temperature difference is low. The signal detected by the detecting device is very faint and have high-frequency noise, so we must amplify signal and degrade the high-frequency noise. Then we design a fully differential amplifier combined with a third order Butterworth Sallen-Key low-pass filter. The differential amplifier can get not only large swing and high gain but its noise is low under the normal temperature. Three-order low pass filter is implemented by one order Sallen-Key circuit and two-order Sallen-Key circuit.