Topmetal-II−: a direct charge sensor for high energy physics and imaging applications

Topmetal-II-, a direct charge sensor, was manufactured in an XFAB 350 nm CMOS process. The Topmetal-II- sensor features a 72 x 72 pixel array with an 83 mu m pixel pitch which collects and measures charge directly from the surrounding media. We introduce the implementation of the circuitry in the sensor including an analogue readout channel and a column based digital readout channel. The analogue readout channel allows the access to the full waveform from each pixel through a time-shared multiplexing. The digital readout channel records hits identified by an individually settable threshold in each pixel. Some simulation and preliminary test results are also discussed.