Power supply solution for nRF51822

[Jerome Bioret]

Hello all,

In many thread I can read that it is not recommended to use the internal DC-DC converter to supply the nRF51822. Can you tell me why it is better to use an external DC-DC with the internal LDO ?

It's important to know that because it makes a significant change on the BOM cost.

Thanks, Jerome

[syntroniks]

It all seems to come down to efficiency. The DC-DC converter becomes an attractive option when current draw is relatively high (read: radio on, ~15-20mA). The LDO on the other hand, wins out in low draw situations (read: most of the time).

If you are drawing enough current to make a DC-DC more efficient than the LDO I would operate the device off of 1.8 volts - otherwise we just use the internal LDO and no switching converters.