New counting ASIC for X-ray imaging devices

A new preamplifier concept dedicated to X-ray counting devices was tested through a small 32×32 pixel matrix ASIC design. The schematics uses a charge transfer amplifier principle. Design was optimized to allow a high sensitivity (675 mV/ke−) together with a high counting rate (minimum Δt: 150 ns at 3000e− input pulses), a low noise (150 rms electrons) and a low pixel power consumption (4.6 μW). A chip in 0.35 μm technology was processed and electronically tested. Design and performance are presented.