Raspberry Pi 15.3W USB-C Power Supply
This is the best power supply we have found for zynthian. It's also the official power supply for Raspberry Pi 4.
PSU Model: UNITED STATES
Specification
The official Raspberry Pi USB-C power supply is designed to power the latest Raspberry Pi 4 Model B boards, which were released in June 2019.
5.1V / 3.0A DC output
96-264Vac operating input range
Short circuit, overcurrent and over temperature protection
1.5m 18 AWG captive cable with USB-C output connector
Available in four different models to suit different international power sockets
Available in either white or black