1 Introduction

The TPS61391 is a fully integrated boost converter with an 85-V FET to convert a low input voltage to a higher voltage for biasing the APD. The TPS61391 supports an input voltage ranging from 2.5 V to 5.5 V, the maximum output voltage can reach 85 V. In some applications, for example, mechanically scanning LIDAR, robot LIDAR, or laser distance meters, negative voltage biased APD were also used, the voltage range is from -20 V to -150 V or even lower. Those negative supply voltage need to be of high precision, low ripple, and small solution size.

This application note delivers a low cost, high-precision and small-sized power supply design for the negative-voltage-biased APD application with TPS61391. The output voltage is tightly regulated at a certain value regardless of the line voltage or load current change. This design can cooperate with trans-impedance amplifier, similar to LMH32401 for light detection and ranging (LIDAR) applications, or laser distance measurement systems.