Circuit modeling of SAGCM-APD

In this paper, we present a circuit model for SAGCM (separate absorption, grading, charge and multiplication) APD. It is based on the carrier rate equations in the different regions of the device We deduced the characteristic equations of photo-current and dark current, respectively. According to these current equations, a PSPICE model, which is used in device and circuit simulations, is constructed. Using this model, we simulated the main parameters of SAGCM APD, such as photo-current, dark current and gain. The results are excellent agreement with experimental data over a wide range of bias voltage This model can also be applied to SAM APD and SACM APD by modifying its equivalent circuits.