First Test Results of the Trans-Impedance Amplifier Stage of the Ultra-fast HPSoC ASIC

We present the first results from the HPSoC ASIC designed for readout of Ultra-fast Silicon Detectors. The 4-channel ASIC manufactured in 65 nm CMOS by TSMC has been optimized for 50 um thick AC-LGAD. The evaluation of the analog front end with \b{eta}-particles impinging on 3x3 AC-LGAD arrays (500 um pitch, 200x200 um2 metal) confirms a fast output rise time of 600 ps and good timing performance with a jitter of 45 ps. Further calibration experiments and TCT laser studies indicate some gain limitations that are being investigated and are driving the design of the second-generation pre-amplification stages to reach a jitter of 15 ps.