Characterization of FEEWAVE, a low-power waveform digitizer ASIC with 15-ps time resolution

Purpose FEEWAVE is a chip with a waveform digitizer based on a switched capacitor array (SCA). A SCA uses capacitor arrays to store waveforms and exhibits low-power consumption and high time resolution performance. However, the limitations of the chip manufacturing process induce sampling interval and digitization deviations between different cells, which affects the performance of the chip. Methods Calibration was performed on the SCA sampling part on the FEEWAVE chip to obtain more accurate digitized output and time intervals between the sampling cells. Experiments were carried out according to the proposed amplitude and time calibration methods, and the time resolution of the chip was further improved by a fitting algorithm. Results and conclusion Through the calibration algorithm, the time resolution of the SCA sampling part of the chip reached 9.0 ps after calibration. In the self-test of the electronics time performance, the time measurement after leading-edge fitting and calibration was approximately 12.3 ps. In the joint test with silicon photomultiplier detectors, the time resolution of the SCA part was low and comparable to the resolution of the oscilloscope after calibration algorithm and waveform fitting.