CAEN V792N ADC

This short section describes the behavior of the V792N ADC from CAEN. In the current setup a blue LED is coupled to an XP2020 PMT by an optical fiber and the light intensity is adjusted such that the PMT provides a signal between about 10mV and 40mV. The HV of the PMT is set at -1700V. The signal is connected to an amplifier of 10 and then connected to a linear FAN IN/OUT. The DC output of the FAN can be adjusted and is changed between 0 and 15mV in this test. The ADC V792N is a charge integrating ADC with a 12bit digitizer and has a sensitivity of 50fC per channel. There is a built in threshold for each channel that varies between about 50 and 60 bins. In this test channel 4 of the ADC is used and its threshold is found to be about 55 as shown in the next plot. The gate length is set to 63.6ns.