give external supply to nrf51

[nordicbeginner]

hello there,

i am giving external supply to nrf51. my external supply is usb 3.3 v. but when i connect it with nordic and then if i check it on multimeter , it shows me 2.12 v. can you tell me why??

[Roger Clark]

What are you using to supply the power ?

USB is 5V not 3.3V so whatever you are using must be regulating 5V down to 3.3V, or perhaps when you say its a USB supply, you mean something akin to a phone charger ?? but 3.3V ???