nrf51822 - jlink 0.76V

[normanfust]

Hello,

I connected the nrf module to jlink as described:

• vdd(nrf)-----3.3V    
• gnd(nrf)-----gnd
• SDO(nrf)-----SWDIO(jlink)
• SCLK(nrf)-----SWCLK(jlink)
• 3.3V------VTref(jlink)
• gnd------gnd/pin20(jlink)

After executing jlink.exe I receive the following VTref = 0.763V. Am I missing something?

[Turbo J]

Triple-check the cable connections.

[bjorn-spockeli]

Are you powering your nRF module from an external supply or battery?

[normanfust]

@Turbo J already did, @Bjorn Spockeli from an arduino which has a 3.3 V output To make things more clear at the input of BLE I have 3.3V but jlink reads around 0.75V instead.

[bjorn-spockeli]

Have you measured that VDD on the nRF51822 module is actually 3.3V?

[normanfust]

Yes, it is 3.3V