BLDC Motor Controller PCB Design
Thought
Work done
- Project was named 35mm STM32 BLDC Controller and a specification file was created.
- Added and wired the core schematic: STM32H725-family MCU, DRV8316-family motor driver, MA702 encoder, CAN transceiver, 5V buck, 3.3V LDO, USB-C + USB ESD, dual JST-GH CAN connectors, XT30 input, motor phase connector, and support passives.
- Set the PCB to 35 x 35 mm with a 4-layer stackup intent: top signal/power, L2 ground plane, L3 power plane, bottom signal/encoder.
- Enforced the critical MA702 placement: U3 is set to bottom layer at board center (0 mm, 0 mm).
- ✅ Specified functional components were added, with documented substitutions where exact library MPNs were unavailable.
- ✅ ODrive Micro-style key schematic wiring was applied for PWM, current-sense outputs, MA702 SPI, CAN RX/TX, and USB DP/DM through ESD/series resistors.
- ✅ Board size and 4-layer stackup were configured.
- ✅ MA702 exact center/bottom placement was enforced.
- ❌ Full component placement, routing, dense DRV8316 via-in-pad thermal array, and ERC/DRC cleanup are still incomplete.
- Finish PCB placement for all remaining components, especially edge connectors and DRV8316 power-stage clustering.
- Add/verify the DRV8316 thermal via-in-pad GND array.
- Route USB/CAN/high-current motor and power nets, then review and clear ERC/DRC issues.
- Note: execution stopped because credits were exhausted before layout/routing/final checks could be completed.
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35mm STM32 BLDC Controller Specification
Goal
Design a high-performance compact BLDC motor controller PCB on a strict 35 mm x 35 mm 4-layer board.
Required major components
- STM32H725RGV6 MCU, LQFP-64
- TI DRV8316CRGFT integrated-FET BLDC driver
- MA702 magnetic encoder, QFN-16, bottom layer at exact board center
- MCP2542WFD CAN transceiver, SOIC-8
- TLV62080 5 V buck converter
- TPS7A2033 3.3 V LDO
- USB-C connector with USBLC6-2 ESD protection
- Two 4-pin JST-GH CAN daisy-chain connectors
- XT30 or direct-18AWG power pads
Critical ODrive Micro-style pinout
- STM32 PA8/PA9/PA10 -> DRV8316 INHA/INHB/INHC
- STM32 PB13/PB14/PB15 -> DRV8316 INLA/INLB/INLC
- DRV8316 SO1/SO2 -> STM32 PA0/PA1
- MA702 SPI -> STM32 PA4 CS, PA5 SCK, PA6 MISO
- STM32 PB8/PB9 -> MCP2542WFD RX/TX
- USB-C D+/D- -> USBLC6-2 -> STM32 USB_DP/USB_DM
Layout constraints
- Board: 35 mm x 35 mm
- Stackup: L1 Signal/Power, L2 solid GND, L3 power planes, L4 Signal/Encoder
- Outer copper intent: 2 oz
- Dense GND via-in-pad thermal array required under DRV8316 thermal pad
- Connectors and power pads at board edges
Goal
Required major components
Critical ODrive Micro-style pinout
Layout constraints
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