Anode Front-end Boards

The emphasis on anode readout is on the accuracy of timing instead of pulse height. Each input channel of the anode FEB is a ganged group of wires (10 to 20) from a layer. Each front-end board is designed to read out a section of a chamber layer which is 16 wire groups wide. The functionality of the anode FEB is shown below.

The input signals go into 16-channel preamplifier-shaper-discriminator ASIC's. The amplifiers are similar to the ones on the cathode FEB, but optimized for the summed anode input capacitance. The signals are shaped with shaper peaking time of 30ns and sent into discriminators. The discriminator output pulses are sent to the ALCT board where they are latched and the latched bits are used to form the Anode Local Charge Track (ALCT) and to determine the bunch crossing time of the track segment. Each AFEB contains 1 Preamp-Shaper_discriminator ASIC.