AD8 Amplifier-Discriminator

The ET Enterprises AD8 amplifier discriminator is designed to be used with the MCS-CT3 counter timer module for photomultiplier counting applications but is suitable for counting all sources of TTL pulses. An output pulse of fixed width and amplitude is produced for each photomultiplier output pulse that exceeds the input discriminator threshold level. The threshold level is fixed at -2mV, which is sufficiently sensitive to enable most photomultipliers with 10 or more dynodes to operate in single photon counting mode.

  • 150 MHz capability
  • high input sensitivity and low noise
  • signal and power compatible with the MCS-CT3
  • input overload protection
  • suitable for use with negative or positive HV photomultiplier operation
  • easy to use

Download AD8 data sheet

Specification Summary


Power Input

    voltage input +5V  
    current input (no signal) 40mA  
    current input (signal =150Mcps) 110mA  

Signal Input

    connector BNC socket  
    discriminator level -2mV  
    input impedance 50 ohms  

Signal Output

    level TTL high level(terminated)  
    pulse pair resolution (17ns output) 25ns  
    pulse pair resolution (10us output) 10us  
    output impedance 50 ohms  
    deadtime same as pulse-pair resolution  
    signal count rate (17ns output) max 150Mcps (with deadtime correction)  


    weight 140 g  
    temperature range (operating) +5 to +55 deg C  





© ET Enterprises Limited 2011-2015
ET Enterprises is a trading name of ET Enterprises Limited. Registered in England & Wales, company number 06081468.