Design and performance of analog circuit for the wide field of view Cherenkov telescope array of LHAASO

The Wide Field of View Cherenkov Telescope Array (WFCTA) is an important part of the Large High Altitude Air Shower Observatory (LHAASO) project. A high-resolution and low-relative deviation charge measurement is required over a dynamic range of 10 photoelectrons (p.e.) to 32,000 p.e. in the electronics readout system of the WFCTA. The analog circuit is one of the crucial parts in the electronics readout system. Because of the large dynamic range of the signals, a dual-gain electronics channel has been designed. In other words, for the signals from a SiPM, we designed two channels with the similar structures and different gains When these two kinds of channels are placed on two different Printed Circuit Boards (PCBs), it reduces the crosstalk between the large gain channels and the small gain channels. Tests have been conducted to evaluate the performance of the electronics readout system under different temperature conditions. Results indicate that accurate charge measurements can be achieved, ranging from 10 p.e. to 32,000 p.e., and that the system is capable of adapting to the temperature environment of the plateau where the altitude is more than 4000 m.