The Raspberry Pi foundation recently announced in a blog post the release of improved version of their Power-over-Ethernet solution – Pi PoE+ HAT (plus version). The new version supersedes the older Pi PoE HAT. The new version implements 802.3at PoE+ standard, and thus can deliver more power. The designers have made careful changes to handle this extra power and yet run it cooler. The module costs $20 at the RPi store.
The original version PoE HAT will continue in production, but like everyone in the electronic industry, Raspberry Pi is also finding it difficult to manage supply chains due global semiconductor shortage. The PoE+ HAT will be available on stores starting from June this year.
The original PoE HAT used the 802.3af PoE standard which delivers a maximum power of 13W. But the newer standard can deliver up to 25W. This will allow designers to use more capable USB devices attached to the Raspberry Pi SBCs. A comparison table is provided by RPi.
|PoE HAT||PoE+ HAT|
|Standards supported||802.3af||802.3af, 802.3at|
|Maximum output current||2.5A||5A|
|PCB||4 layers, 2oz copper||4 layers, 2oz copper|
|Compatible with||Raspberry Pi 3B+, 4B||Raspberry Pi 3B+, 4B|
Delivering more power requires better thermal management. RPi engineers have achieved this by using the Microchip PD70224ILQ ideal diode in the new design. The new transformer is interesting too. It uses the Bourns’s planar transformer core. This is essentially a split ferrite core through which a PCB with winding traces is inserted. This makes the design compact and neat, unlike the previous one.
PoE+ HAT Specifications
- Standard: IEEE 802.3at-2003 PoE
- Input voltage: 37-57 V DC, Class 4 device
- Output power: 5 V DC/4 A
- Cooling: 25 mm × 25 mm brushless fan delivering 2.2 CFM for processor cooling
- Features: Fully isolated switched-mode power supply, Fan control
- Operating temperature: 0 °C to +50 °C