A suitable choice of breakpoint can easily accommodate the necessary measurement accuracy with only 12 bits of FADC range. Such devices have been used successfully in many experiments. Calibration must be done carefully. Square root op amp. Eckart Lorenz mentioned the existence of amplifiers that can produce a square root function, so the output is proportional to the square root of the input.
Calibration is probably more demanding than for the bi-linear amplifier.
We evidently need some technical discussions of the relative performance of the different proposals. The choice may also affect the layout of the front end boards. Front end boards Hartmut Gemmeke and his colleagues have done extensive work on the design and organization of the front end boards. They have simulated the system in VHDL, and Hartmut presented detailed cost estimates already at the CERN meeting in November. Each board will contain the electronics for 10-12 pixels.