Raspberry Pi 5 HAT Design Discussion
1:07
Checking if I can make the changes for you.
Here’s the components change plan to add the core parts you requested. This turn focuses only on enumerating the parts to add (no wiring yet). I selected specific, industrial-friendly MPNs. If you prefer alternatives (e.g., eFuse vs PTC), say so and I’ll adjust.
Added components
Table
| Part Name | Purpose | Manufacturer Part Number | Quantity | Footprint | Datasheet link |
|---|---|---|---|---|---|
| 40-pin Pass-through Header (RPi HAT stackable) | Provides stackable GPIO connection to Raspberry Pi 5 and pass-through to other HATs | M20-6102045 | 1 | 2×20 TH | |
| HAT+ ID EEPROM (3.3 V) | Stores HAT identification; connected only to GPIO0/1 with 3.3 V pull-ups | 24LC32A-I/P | 1 | DIP-8/ SOIC-8 (prefer SOIC-8) | |
| I2C Pull-up Resistor 4.7 kΩ | Pull-up on 3.3 V ID bus (GPIO0/1) | RC0603FR-074K7L | 2 | 0603 | |
| Decoupling Capacitor 100 nF | Local decouple for ID EEPROM | CL10B104KB8NNNC | 1 | 0603 | |
| I2C Level Translator | Bidirectional I2C translation between Pi 3.3 V and device 5 V busses | PCA9306DCUR | 1 | VSSOP-8 | |
| I2C Pull-up Resistor 4.7 kΩ | Pull-up on Pi-side I2C1 (3.3 V) | RC0603FR-074K7L | 2 | 0603 | |
| I2C Pull-up Resistor 4.7 kΩ | Pull-up on device-side I2C (5 V) | RC0603FR-074K7L | 2 | 0603 | |
| Decoupling Capacitor 100 nF | Local decouple for PCA9306 | CL10B104KB8NNNC | 1 | 0603 | |
| PWM Controller (16-ch, 12-bit) | Core PWM engine at 5 V; exposes 6 buffered channels + 10 spare | PCA9685PW | 1 | TSSOP-28 | |
| Address Solder Jumpers (A0..A5) | Configure PCA9685 I2C address; default 0x40 | SJ-3523-SMT | 6 | 3-pad SJ | |
| OE Pull-up Resistor 10 kΩ | Holds OE deasserted by default; optional link to GPIO | RC0603FR-0710KL | 1 | 0603 | |
| Decoupling Capacitor 100 nF | Local decouple for PCA9685 | CL10B104KB8NNNC | 1 | 0603 | |
| Bulk Capacitor ≥47 µF | Local bulk for PCA9685 5 V rail | EEE-FT1V470AP | 1 | SMD Elec | |
| Inverting Schmitt Buffer (hex) | Robust 5 V output buffering for 6 primary channels | SN74HC14D | 1 | SOIC-14 | |
| Series Resistor 47 Ω | Damping resistor at each buffered output (CH1..CH6) | RC0603FR-0747RL | 6 | 0603 | |
| Optional RC Cap Pad 0–100 pF (DNP) | Edge-rate tuning near connector per channel | CL10C100JB8NNNC | 6 | 0603 | |
| Low-cap ESD TVS (2-line) | Per-channel ESD protection at connector edge | ESD9M5V-DL | 6 | SOD-923 or DFN | |
| Screw Terminal 3-pos, 5.0 mm, vertical | Field I/O for each primary channel: PWM, +5 V, GND | 691137710003 | 6 | TH 5.0 mm | |
| Spare Channel Series Resistor 220 Ω | Series limit for 10 spare outputs to pads | RC0603FR-07220RL | 10 | 0603 | |
| Test/Expansion Thru-hole Pads | Expose spare channels (DNP connectors) | TP_TH_1.0mm | 10 | TH pad | ___ |
| Decoupling Capacitor 100 nF | Local decouple for SN74HC14 | CL10B104KB8NNNC | 1 | 0603 | |
| External 5 V Input Terminal (2-pos) | Optional field power entry for terminals | 691137710002 | 1 | TH 5.0 mm | |
| Resettable Fuse PTC (hold ~1.1 A) | Protect external 5 V input path | MF-MSMF110/16X | 1 | 1206 | |
| TVS Diode SMBJ5.0A | Surge/ESD at external 5 V entry | SMBJ5.0A | 1 | SMB | |
| Power Inductor 1 µH ≥1 A | LC filter for external 5 V | SRN4018-1R0M | 1 | 4.0×4.0 mm | |
| Ceramic Capacitor 10 µF, 25 V X7R | LC filter output decoupling | CL10A106MQ8NNNC | 1 | 0603 | |
| Bulk Capacitor 100 µF | External 5 V bulk after filter | EEE-FT1E101AP | 1 | SMD Elec | |
| 0 Ω Link (DNP) | Backfeed link between filtered 5 V and Pi 5 V (default open) | RC0603JR-070RL | 1 | 0603 | |
| Solder Bridge (OE to GPIO option) | Optional route OE to Pi GPIO for global mute | SJ-3523-SMT | 1 | 3-pad SJ |
Notes
- If you’d rather use an eFuse (integrated OCP/OVP) instead of a PTC, I can swap the PTC line item for a common eFuse (e.g., TPS2595x family) and add its passives.
- If you prefer SN74AHC14 for sharper edges, I can substitute it one-for-one.
- Test pad symbol is a placeholder; we’ll place 10 labeled pads for spare channels.
Would you like me to proceed with wiring the connection skeleton in the next step after these components are added?
214 days
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