The expansion board is designed to accept power from either the DC barrel jack (J4) or the USB Type-C connector (J7). When both the DC barrel jack and USB power are applied, the board takes its power through the barrel jack by default.
When it is booted, the input source cannot be switched without rebooting the platform.
It is recommended to use the DC power input jack while developing on the platform because it is easier to ensure input power quality over a direct DC connection.
Any source connected to the J4 input must meet these specifications:
Voltage: 12.0 volts, ±3%
Current: 2.7 amps, minimum – the expansion board contains a 3.5 amp fuse
Safety Ratings: Listed LPS or Class 2
When using the USB Type-C as a power source, the developer must confirm the host system provides the required quality and capacity of input power. Excessive loads on a Type-C power bus can cause development platform and/or host instability.
As an Intel® Joule™ module-based project matures, the workload and platform power data can be used to guide an optimal power source that meets the intended form-factor goals.