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High Voltage Boost for Avalanche Photo Diodes in LiDAR Applications – Reference Design

February 26, 2020 by Paul Shepard

A design challenge that appears when working with LiDAR systems is providing a high voltage power supply to bias the avalanche photo diode (APD) sensor, as these kinds of photo diodes can need up to 300V depending on their size. The power supply must be cost effective and pass the EMC regulations in the automotive industry.

The MPQ3910A reference design from Monolithic Power Systems uses the MPQ3910A to control a boost converter working in DCM. This allows the use of cheap small sized components and to overcome the limitations due to very high duty cycle.

The boosted voltage is effectively doubled through a charge pump to achieve >350V output capability while still using lower voltage rating semiconductors, which are smaller, cheaper and have better performance than their high voltage counterparts.

MPQ3910A reference design circuit board

Summary of Features

  • AEC-Q100 Qualified
  • CISPR-25 Class 5 Compliant
  • Wide 5V to 35V operating input range
  • Single N-Channel MOSFET gate driver with 12V 1A capability
  • Programmable frequency range: 30kHz - 400kHz
  • External sync clock range: 80kHz - 400kHz
  • Programmable soft start (SS)
  • Over-current protection (OCP)
  • Output over-voltage protection (OVP)
  • Short-circuit protection (SCP)
  • Internal LDO with external power supply option
  • Pulse-skipping operation at light load
  • Available in MSOP-10 Package