Fsae pihat

FSAE Pi HAT USB Boost / PD Module

What this project is

This PCB is the external 20 V USB-C PD → 24 V boost module used with the main Pi HAT. It pairs a PDC004 V2 USB-C PD trigger (fixed 20 V) with an MT3608 boost module to generate 24 V for PoE injection on the base station antenna and for convenient bench power during testing. This is a companion PCB to the main Pi HAT.

Why I made it

Since the current here would be pretty low, I decided to use a MT3608 and PDC004 PD module (I already have one, and the design seems pretty good; really big power plane on bottom) on a separate PCB instead of putting a boost converter on the HAT.

The MT3608 module also should be able to handle the current required (2 A) for the 24 V PoE injection, which should be around 1 A peak. The IC itself is pretty capable; there often just is not a great component selection or insufficient decoupling/filtering. I remembered this GreatScott video where he added a 2.2 µF 1210 capacitor to the output of the MT3608 to improve output ripple, so I added C1 (2.2 µF).

Pictures

Schematic

View schematic online (KiCanvas)

PCB

View PCB online (KiCanvas)

Wiring (off-board)

Connect to the main HAT J3 and a USB-C PD supply:

USB-C PD supply (20 V negotiated)
    │
    ▼
PDC004 module (J2, bottom of this PCB) ──► +20 V rail
    │
    ▼
MT3608 boost (U1, top of this PCB) ──► +24 V
    │
    ▼
3-pin header J1 ──► wires ──► Deutsch connectors ──► main HAT J3

For the PCB, the PD module is surface mount on the bottom and the MT3608 on the top, since both have large pads on both sides with vias.

Bill of materials

Designator	Footprint / package	Qty	Value	Notes
J1	PinSocket_1x03_P2.54mm_Vertical	1	Conn_01x03_Socket	To main HAT
J2	PDC004 Module	1	PDC004 PD Trigger	Fixed 20 V USB-C PD; AliExpress module
U1	MT3608 Module	1	MT3608 Boost	AliExpress / generic boost module
C1	C_1210 (hand solder on module)	1	2.2 µF, 50V X7R 1210 CL32B225KBJNNNE	Output stability cap; solder on MT3608 output