This paper presents a 4-channel avalanche photodiode readout ASIC for the electromagnetic calorimeter in the 2–7 GeV high intensity electron positron accelerator. A large detector capacitance of the avalanche photodiode will increase equivalent noise charge and extend rise time of the front-end preamplifier, resulting in attenuated energy and time resolution of the ASIC. A low-noise preamplifier and a 5th-order high-linearity shaper were proposed to decrease the noise induced by a 270 pF detector capacitance. The ASIC is fabricated using a standard 0.18-$\mathrm{\mu }$m CMOS technology, and the die size of the prototype chip is 1.1 mm $\times$ 2.4 mm. The input charge range of the ASIC is from 4.8 fC to 400 fC. The event rate of the ASIC can achieve 400k count/s. Nonlinear error of the shaper is less than 2%. The measured signal to noise ratio is better than 7.8 at a shaping time of 800 ns. The timing resolution of the ASIC is better than 300 ps at an input charge of 100 fC.

本文介绍了用于2-7 GeV高强度电子正电子加速器中的电磁量热计的4通道雪崩光电二极管读出ASIC。雪崩光电二极管的较大检测器电容会增加等效噪声电荷并延长前端前置放大器的上升时间，从而导致ASIC的能量和时间分辨率降低。提出了一种低噪声前置放大器和一个五阶高线性整形器，以减少由270 pF检测器电容引起的噪声。ASIC是使用标准0.18-$\mathrm{\mu }$m CMOS技术，原型芯片的芯片尺寸为1.1毫米 $\times$2.4毫米 ASIC的输入电荷范围为4.8 fC至400 fC。ASIC的事件率可以达到400k count / s。整形器的非线性误差小于2％。在800 ns的整形时间，测得的信噪比优于7.8。在100 fC的输入电荷下，ASIC的时序分辨率优于300 ps。