Front-End Electronics

Several ASICs support the APV readout chip in the front-end. In the readout path, the APVMUX is used to multiplex the output of two APV25 chips onto a single transmission channel. On the control and monitoring side [54], the PLL-Delay splits clock and trigger signals from a common line and is used to fine-tune clock and trigger delay. The DCU monitors voltages, currents and temperature. Finally, the CCU is responsible for the communication with the control room and acts as an $\rm I^2C$ bus master. Since FEC and CCU are a logical unit, they will be discussed together in a later section.