The schematic incorporates a P-channel MOSFET (e.g., AO3401 ) acting as a high-side switch. Controlled by the internal MCU, this switch routes 5V power to Pin 19 of the debug header when enabled via software. Detailed Pinout and Interface Connections
While many "V9 clones" exist, they often suffer from poor voltage shifting, resulting in failure to detect targets or damaged hardware. jlink v9 schematic