Motor Driver and Power PCB Review
Review a mixed-power motor-control PCB with safe separation, thermal design and measurable bring-up limits.
EDA workflow: KiCad / Altium / compatible EDADesign requirements
- Logic and motor power domains clearly identifiednDriver selected for stall current with engineering marginnReverse polarity, over-current and inductive transients controllednCurrent-sense and supply test points accessiblenEmergency disable defaults to safe state
Required deliverables
- Reviewed schematic and calculations
- ERC, DRC and high-current path report
- Thermal design evidence
- Gerber/drill and fabrication drawing
- Controlled BOM and alternates
- Assembly drawing and torque notes
- Current-limited bring-up procedure
- Electrical, thermal and functional test report
Schematic and ERC review
| Done | Check | Acceptance criteria | Evidence |
|---|---|---|---|
| Motor driver | Voltage, peak/stall current and thermal limits verified | Calculation and datasheet | |
| Protection | Fuse, polarity, TVS and flyback/current-decay path reviewed | Schematic evidence | |
| Gate/control states | Pull resistors guarantee safe power-up | Truth table | |
| Ground strategy | Current return avoids logic and ADC reference paths | Current-path diagram | |
| Connectors | Voltage/current rating and polarity marking adequate | Part specification |
PCB layout and DFM review
| Done | Check | Acceptance criteria | Evidence |
|---|---|---|---|
| High-current paths | Width, copper weight and temperature rise calculated | IPC-based calculation | |
| Thermal relief | Driver exposed pad and vias follow recommendation | Layout inspection | |
| Loop area | Switching and recirculation loops kept compact | Current-loop markup | |
| Clearance | Motor voltage/transients meet internal design rule | DRC report | |
| Sensing | Kelvin routes used where required | Layout review | |
| Mechanical | Mounting, terminal access and heatsink clearance verified | 3D review |
Gerber and fabrication package
| Done | File or check | Requirement | Evidence |
|---|---|---|---|
| Copper and masks | Correct layers and no unintended exposed copper | Gerber viewer | |
| Drill map | Terminal, mounting and thermal-via sizes verified | Drill report | |
| Fabrication notes | Copper weight, finish, material and current requirements stated | Fab drawing | |
| Assembly drawing | Polarity, pin 1 and no-fit components clear | PDF drawing | |
| BOM | Current/voltage/temperature ratings and alternates controlled | BOM review | |
| Release archive | Revision and checksum match approved design | Release record |
Assembly bring-up and test
| Done | Test | Expected result | Instrument | Safety limit |
|---|---|---|---|---|
| Unpowered checks | No short and expected gate/control bias | DMM | Motor disconnected | |
| Logic power | Correct logic rail and safe enable state | Bench supply | Low current limit | |
| Motor rail | Stable rail with driver disabled | Scope and DMM | Current limit enabled | |
| PWM output | Correct driver waveform into safe unloaded setup | Oscilloscope | Keep clear of moving parts | |
| Current sense | Reading agrees with reference current | DMM and scope | Stay below driver/motor limits | |
| Thermal run | Temperature stabilises below approved limit | Thermal camera | Stop at defined maximum |
Bill of materials
Download BOM CSV| Qty | Reference | Value | Package | Manufacturer part | Supplier / SKU | Notes |
|---|---|---|---|---|---|---|
| 1 | U1 | Motor driver | HTSSOP | DRV8876PWPR | Supplier / TBD | Size for stall current |
| 1 | F1 | Resettable fuse | 1812 | MF-MSMF200-2 | Supplier / TBD | Verify trip curve |
| 1 | D1 | TVS diode | SMB | SMBJ18A | Supplier / TBD | Match motor rail |
| 1 | R1 | Current shunt | 2512 | WSL2512R0500FEA | Supplier / TBD | 50 mΩ, rated power |
| 2 | J1-J2 | Power terminal | 5.08 mm | 1935161 | Supplier / TBD | Current rated |
| 4 | C1-C4 | 100 nF | 0603 | Generic X7R | Supplier / TBD | Logic decoupling |
| 1 | C5 | 470 uF | Radial | Low-ESR rated part | Supplier / TBD | Motor transient bulk |
Assembly documentation
- Inspect thermal-pad solder coverage with the approved method.
- Torque high-current terminals to the manufacturer specification.
- Keep no-fit options clearly identified in BOM and drawing.
- Power logic first where the driver sequence requires it.
- Run initial motor test unloaded and mechanically restrained safely.
- Record no-load, startup and controlled stall/current-limit behaviour.
Fabrication notes
- State copper weight and finished dimensions explicitly.
- Heavy-copper or current requirements require fabricator confirmation.
- Do not change thermal-via fill/cap process without review.
- Use appropriate creepage/clearance for the actual maximum transient voltage.
- Panel tabs must not weaken high-current terminal edges.
- Assembly vendor must preserve current-shunt value and tolerance.
Project documentation
Release workflow
- Freeze requirements and confirm the exact component variants.
- Complete schematic/ERC review and resolve every approved exception.
- Complete layout, DRC and independent Gerber review.
- Release revision-controlled BOM, fabrication and assembly documents.
- Assemble using controlled substitutions and inspection records.
- Power through current limiting, record measurements and approve production only after all mandatory tests pass.