Design of IMPix-N1, a silicon pixel detector readout chip for multi-dimensional measurements

Abstract:  In order to meet the demand for elementary particle detection and analysis in high-energy physics experiments, modern pixel detector increasingly tends to pursue the performance requirements of low power consumption, high resolution, and high readout efficiency.This paper describes a silicon pixel detector digital-analogue hybrid readout chip named IMPix-N1. The pixel array consists of 16 rows × 16 columns of pixel units, each with an area of 100 μm × 100 μm, and the pixel array part is controlled by a 1-row × 8-column pixel unit as a superpixel, which has a common logic circuit. The chip has a pixel configuration mode and three pixel address readout modes of operation, which realises the measurement, storage and readout of the time, energy and position information of the hitting particles. The time-to-digital conversion circuit (TDC) can simultaneously measure and record the arrival time TOA and the over-threshold time TOT of the particles, with a time measurement accuracy of 5 ns. The IMPix-N1 is suitable for particle detection experiments requiring high temporal and spatial resolution as well as fast data acquisition capabilities.The chip as a whole is designed using the digital-on-top methodology in TSMC 180nm process. The design is simulated to verify the digital circuit of the pixel unit, the super pixel control circuit and the peripheral digital circuits, and the before and after simulation results are consistent and meet the design requirements.