I can help design this HAT, but I can’t make schematic changes right now because this account has no available ACUs, so AI execution features are unavailable.
What’s been accomplished so far:
The project is newly created and currently empty: no components, nets, or schematic wiring yet.
I reviewed your requirements for a Raspberry Pi 5 UPS HAT with:
6–18 V barrel input
5 V / 3–5 A buck output for Pi 5
1-cell LiPo charging
battery-backed 5 V UPS path
40-pin Raspberry Pi header power connections
4-pin I2C sensor header tied to Pi GPIO I2C pins
What remains to be done once ACUs are available:
Select concrete ICs for the buck regulator, LiPo charger, boost/power-path stage, protection, and connectors.
Add the Raspberry Pi 40-pin HAT header and external I2C header.
Wire:
5 V UPS output to Pi pins 2 and 4
GND to Pi pins 6/9 and system ground
3.3 V from Pi pin 1 to I2C VCC
SDA to Pi pin 3
SCL to Pi pin 5
Add support parts: inductors, capacitors, feedback dividers, protection diode/TVS/fuse, battery connector, and pull-ups if needed.
Run ERC/design review and produce a bring-up checklist.
Recommended architecture when work can continue:
Use a high-current 5 V buck regulator from the 6–18 V barrel input.
Use a dedicated 1-cell LiPo charger from the input supply.
Use a 1-cell boost converter rated for Raspberry Pi 5 load current, with ideal-diode or power-mux behavior so the Pi stays powered when input is removed.
Treat the Pi 5 as a high-current load: design for 5 V at 5 A if you want margin.
Once ACUs are available, I can proceed with component selection and schematic wiring directly in the project.
Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
General Purpose Thick Film Standard Power
and High-Power Chip Resistor
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film
Features:
- RMCF – standard power ratings
- RMCP – high power ratings
- Nickel barrier terminations standard
- Power derating from 100% at 70ºC to zero at +155ºC
- RoHS compliant, REACH compliant, and halogen free
- AEC-Q200 compliant