Design and test of a CMOS low-power mixed-analog/digital ASIC for radiation detector readout front ends

A new CMOS low-power mixed A/D ASIC for radiation detector readout front ends is presented. First, we recall the principle of radiation detection system before describing the whole architecture of the circuit. The discussion is then focused on the low-power issue. By means of an innovative 128:1 analog multiplexer, we show how we drastically reduced the mean power consumption without sacrificing constraining specifications such as the input range and the readout rate. Testing mixed A/D, but strongly analog IC is also a big issue which is addressed here. Specific built-in test analog sub-circuits have been implemented in the ASIC, along with a JTAG module used to choose the type of test to perform. This module is also used to control and tune the biasing currents of the circuit. Finally, test results are presented and show that all the specifications are satisfied.