Incorrect ADC/pC value for minimum gain used in signalservices_sbnd.fcl
The ADCPerPCAtLowestASICGain (and ADCTicksPerPCAtLowestASICGainSetting) parameters in signalservices_sbnd.fcl are set to 13198 ADC/pC.
Assuming 12 bit ADC with 0-1.8V range and a 4.7 mV/fC minimum gain, the value should be:
4.7 mV/fC x (2^12 ADC/ 1.8V) == 10695 ADC/pC
The current value is set as 13198 ADC/pC but it is unclear why this value is used,
Original message from Michelle:
cc’ing people who can change SBND simulation parameters (summary for you folks - there’s a number in the simulation fcl files that should be changed for the COTS ADC because the input range of 0-1.8V is different than the originalADC design, which was 0-1.6 V. Looks like someone perhaps changed this parameter by 1.8/1.6 instead of 1.6/1.8 and now it’s 40% too big???) michelle