Is the DC/DC converter enabled when running ble_app_beacon?

[Magnus]

Is the DC/DC converter enabled when running ble_app_beacon?

Or is it only the LDO that is enabled?

I am running the application on nRF51822-DK.

BR Magnus

[Stian Røed Hafskjold]

DC/DC is not enabled by default in the 'ble_app_beacon' example. You should also check out this thread on DC/DC: https://devzone.nordicsemi.com/question/685/ldo-vs-dcdc-nrf51822/

[Magnus]

Thanks for the answer. When I am measuring the voltage over the capacitor C10 (i.e. DEC2 and output from internal LDO according to figure 10 in chapter 11.1.1.2 and page 44 in nRF51 series reference manual v2.1) for nRF51822-DK I am measuring a value between 0.8V-1V. Shouldn't this value be something around 1.8V? For the moment I also have the solderbridge SB1 open. Should I shorten SB1 if I want to use only the LDO and not the DC/DC? BR Magnus

[Stian Røed Hafskjold]

The LDO is turned off when not in use, so if you are measuring the output on DEC2 using a regular voltmeter the voltage reading will be too low. The DC/DC is bypassed internally, so it should not be necessary to shorten SB1.

[Magnus]

Hi and thanks for your information. I saw that the voltage is changing when mesuring at DEC2 with oscilloscope and the peak voltage is ca 1.8V. When the LDO is turned off is it the mode called system off? Are there any detailed data information for the internal LDO to compare with for example an external LDO. BR Magnus

[Stian Røed Hafskjold]

There is no direct relationship between the LDO and system off mode, but when nothing uses the analog 1.8V, it will be turned off. Since the radio is turned off in system off mode, the 1.8V will also be turned off, so I guess there is an indirect correlation between those. We don't provide any detailed information on the LDO except what you can find in the product specification. Sorry about that.