Readout Design On Novel GaAs/InGaAs Quantum Effect Photodetector

Based on novel GaAs/InGaAs quantum photodetectors have high sensitivity, large dynamic range, etc. features, the CTIA-CDS readout structure has been designed, the source follower CDS circuit has designed further, which could avoid the pixel crosstalk. They are processed by the TSMC0.35μm2P4M n well CMOS technology.The integration time, detector bias voltage, light power and response voltage, noise and so on have contrasted between test results of 0.5μmCMOS process SI and 0.35μm CMOS process CTIA readout circuit which are docking with 2×8 detector array. The CTIA readout structure is able to stabilize bias of the detector, shown 99.8% linearity and over 2V output signal swing. The SI readout structure has higher output signal to noise ratio, smaller chip area and power consumption. Finally, the improved CTIA has design and simulated for improving the dynamic range and sensitivity.Based on test results of the weak signal analog front-end receiver amplifier, the bandgap reference to provide reference voltage and bias voltage, the instrumentation amplifier and bandpass filter were added to weaken noise further.