As the Raspberry Pi and Atmel/Cortex/ESP platforms become more powerful computational processors, they require more power to do so. Powering these devices in Automotive 12V or Industrial 24V applications has become its own challenge.
The process of DC-to-DC voltage regulation has traditionally been a battle of heat and voltage ripple. As technology has evolved, trying to pull 25 watts of power through a proverbial straw has become easier, but is still a constrained subject.
The traditional method would be utilizing a LM7805 or similar 5-volt Linear Regulator. However, drawing 25 watts through a TO-220 or D2PAK package produces a LOT of heat which must be dissipated into a heatsink.
12 Vin to 5Vout is 8 volts dissipated. Drawing 5 amps at 8 volts is a 40 watt dissipation.
The more modern approach is to use high frequency bucking converters to perform the job. In doing so, the LC array produces less heat while providing a stable output.
There is a Power Hat V2 available, however it is best suited for a Raspberry Pi 3, as it only supports a 15-Watt output. It is not ideal for a Raspberry Pi 4 or 5, much less with other accessories (like an LCD).
There are 2 formats currently available with parameters sufficient to power a Raspberry Pi 4 or 5 – supporting 5+ amps at 5 volts when accounting for any accessories.
Tobsun DC-DC Converter, 50W
Drok DC-DC Converter, 50W with Heatsink
Of the two, DROK has an informal datasheet available, and the heatsink gives a better indication of being stable for long-term use.
- Input voltage: 10V-35V
- Output voltage: DC 5V
- Output Current: 10A continuous output at 35 °C
- Conversion rate: max 90%, low heat
- Working temperature: -25 °c to +60 °Industrial-grade
- Dimension: 74 x 74 x 32mm (L x W x H)
- Protection: over-current protection, short circuit protection, overheating protection.