An ASIC design for LHAASO

The ASIC is widely used in the field of high energy physics. Astroparticle experiments benefit from high integration, small size and low power consumption. In this paper an analog chip named ARCHGARD (Analog Readout Chip for High energy Gamma Ray Detector) for high energy physics experiment is introduced. ARCHGARD is a readout chip, in chartered 0.35 μm SiGe technology, for photomultipliers (PMT) array readout. The chip is designed for the Large High Altitude Air Shower Observatory (LHAASO) project. The ASIC integrates 16 independent and auto-triggered channels with variable gain and variable shaping time. It provides analog output for charge measurement, which is performed from 1 up to 3000 photo-electrons (p.e.). The integral nonlinearity of the whole input range is less than 1% and the equivalent input noise is less than 1/10 p.e. Each channel has a trigger output for time measurement.