Jetzt anmelden Die Community freut sich auf dich! Exklusive Features und Content warten. Melde dich kostenfrei an um viel weniger Werbung zu sehen! The left pin is B+ (you can follow the path from the B+ on the right of U2, upper pad of C15, middle pin of U11 and upwards to the left pins of U2 and U3), the right pin is not clear and the middle pin seems to connected to the cooling pad on the upper side. The cooling pad is normally connected to GND. The marking on the IC itself gives no information, my Google-Fu led me to a picture on taobao, it was labeled DC-DC with a lot of chinese letters. This leads me to the conclusion that this is a Voltage regulator with the secondary Voltage on the right pin. I can identify two Voltage markings, 6V and 3.3V, my money would be on it being the 6V-regulator. My imagination seems to show me a circuit path from the upper pin of U3 leading to the upper and left rim of the PCB which then leads via PD0 and JP1 to a test pad labeled "3.3V".