Rework the entire BQ25750 section from official Texas Instruments source material only.
- Use TI BQ25750 datasheet, EVM/reference design, hardware checklist, and preferably TI design files.
- Verify MOSFETs, inductor, current-sense resistors, compensation/reference networks, bootstrap components, input/output capacitors, and all surrounding circuitry.
- Do not use an AI-generated topology as the final implementation.
Configure the charger for the actual battery target.
- 2S2P Li-ion.
- 7.4V nominal.
- 8.4V maximum charge voltage.
- Approximately 5.2Ah capacity.
- Correct charge voltage, charge current, input-current limiting, and protection settings required.
Add a real external 10k NTC battery thermistor connection.
- BQ25750 TS must monitor the battery pack in hardware.
- Charging must suspend outside the safe temperature range.
- TS must not be simulated by fixed resistors.
Implement proper PoE/DC power-path management.
- PoE must not backfeed DC input.
- DC must not backfeed PoE module.
- Source selection must be stable and reliable.
- System must transition between PoE, DC, and battery without interruption.
Size LTE modem power properly from the Quectel EM05 hardware guide.
- Regulator, bulk capacitance, and decoupling must be based on Quectel data, not estimates.
Keep Mosaic/GNSS on its own clean power rail.
- Must be independent from LTE supply.
- Must include local filtering and decoupling.
Add industrial protection.
- Ethernet surge protection.
- USB ESD protection.
- TVS devices on external interfaces.
- Proper chassis/shield grounding strategy.
Ensure all rails have manufacturer-recommended local decoupling and bulk capacitance.
Produce a complete power tree:
- PoE -> power management.
- DC -> power management.
- Battery -> BQ25750.
- BQ25750 -> 5V system rail.
- 5V -> Compute Module, USB hub, and power converters.
- Separate regulated supplies for Mosaic and LTE modem.
Run full ERC and verify the complete power architecture before continuing.