Design of Preamplifier Circuit Used in Transient Optical Detection System
瞬变光探测系统前置放大电路的设计

The preamplifier circuit in a photoelectric detector can directly affect the signal-to-noise ratio (SNR) of a whole detection system. To improve the detection precision of weak photocurrent, a low noise preamplifier circuit for a photoelectric detector based on a photodiode (in photovoltaic mode) and an operational amplifier is designed. The instability in an I/V conversion circuit due to the parasitic parameters of the photodiode is overcome by using a lead correction method to compensate the phase shift caused by the junction capacitance of the photodiode and the input capacitance of the operational amplifier. Finally, the reasons for choosing the relevant parameters of the components such as photoelectric devices and preamplifiers in the design of this low noise photoelectric detection circuit are given.