Power Distribution Board (PDB) - Unarchived
- Andrew Chai
Introduction
Engineer(s):
@Andrew Chai PM, Design Architecture, SMPS
@Kenny Na Sensing + Interface, Design Architecture
@Megan Lee Sensing + Interface, SMPS
@Santosh Erathasari RPP, SMPS
Background:
Unarchived project from the 2024 PDB 12S PDB
A power distribution board (PDB) is used for supplying and distributing power form the main power supply to various circuits and subsystems. In a drone/UAV context, the PDB is responsible for converting and distributing the battery pack voltage to the several electronics on the drone itself.
Reference COTS PDBs:
PDB500[X] ← this is the one being used on Big Quad 2025
What:
Handle 12S input range (40V-50V)
12V & 5V output rails with sufficient current output for downstream electronics
Common voltage rails
Standard connector
Reverse Polarity Protection (RPP)
Short Circuit Protection??
Voltage + Current Sense → maybe need CAN adapter circuit??
high current passthrough (may be difficult if this is taking in the entire bus current)
might be nice to have a discrete implementation of this, as well as I-sense for each rail
Sensing IC without shunt resistor
Redundancy Support (having just one supply rail makes the system single fault susceptible)
Not deemed as important
Proper input + output filtering networks (need to avoid resonant frequency of Li-Po batteries)
High efficiency power conversion system
Can try playing around with different ways to optimize for efficiency ie soft switching, IC selection
Block Diagram
System Requirements
Power Budget^^
12V @ 3-4A
5V @ 4A
3V3 @ 1-2A
3V3_analog LDO <1A
Nice to have short circuit protection on LV rails
Switch Mode Power Supply
Buck Converter ICs
Andrew, Santosh, Megan
Inductor Selection
Tbd
Input Capacitance
Tbd
Output Capacitance
Tbd
Reverse Polarity Protection (RPP)
Santosh
Current + Voltage Sense
Kenny, Megan
Useful Resources/Links
Buck Converters: Buck Converters
RPP: Reverse Polarity Protection Circuits
MOSFETS: FETs
CAN Circuit: ESC CAN Adapter