Hi
We have a CC256xQFNEM board. We use RF1/RF2 connector for communication and apply a 3.3V to pins7,9 of RF2. We test output(PIN5) of U1 1.8V regulator but we have 3.3V on this pin and PIN1 is connected to PIN5( we check with ohm meter). We disassembled R5 resistor and we expected that there is no voltage on VDD_1V8 (refer to schematic of this board) but we have voltage about 2.6 volt. In this state, Pin 5 of U1 regulator have 1V8 that means regulator work fine.
1-Why PIn1 and PIN 5 of U1 are connected?
2-Why after disassembling of R5 we have Voltage on VDD_1V8 and VDD_1V8_LS?(about 2.6)
3- On my board there is no R10 and R7 resistors.when there is no Jumper on J1 on pin have 3.3V and other one have ~2.3V?
Regrads
