Electronics are required to time sample the preamplified and shaped signals from the SDDs. The sampling must be done such that the intrinsic position resolution obtained from analysis of the time samples permits < 10 m position resolution.
The time dependence of the signals from the SDD anodes is related through the SDD drift times to position.
Switch Capacitor Arrays (SCAs) (see Chapter 23)
have been designed to provide
this functionality. They are 128 time bins deep and operate at a
frequency of 27 MHz. Simuilations show that the combined
PASA -- SCA system will perform such that the intrinsic
position resolution is about 10 m for minimum ionizing
particles and SDDs of the current design.