nRF52840 Current Consumption

RE: nRF52840 Current Consumption

ovrebekk — Tue, 16 Jan 2018 08:14:06 GMT

The second line refers to the case when running the internal LDO, that is correct. When using the LDO the current doesn't change with supply voltage, which is why the voltage is not specified. The number is the same regardless.

Best regards

RE: nRF52840 Current Consumption

ZAC — Tue, 16 Jan 2018 07:31:44 GMT

Thanks Torbjørn for tackling the last two questions. Could you please confirm first point, i.e. that the measurement at the second line refers to the case when the internal LDO is used and where VDD is supplied at 3V?

RE: nRF52840 Current Consumption

ovrebekk — Mon, 15 Jan 2018 13:32:02 GMT

The current drawn by the nRF52840 in LDO mode will be the same regardless of the external regulators.
The current measured out of the battery will probably be lower, but this depends on the efficiency of your external DCDC, and the battery voltage.

An ideal DCDC should reduce the current by a factor proportional to the voltage difference. As an example, if the input voltage is double the output voltage, the current should be reduced by a factor of 2.
Obviously an ideal DCDC doesn't exist, but 80-90% efficiency is pretty common.

The I 0dBm(DCDC, 3V) value is the total system current when you run the radio alone, including the clocks and regulators necessary for radio operation.
When calculating current for multiple peripherals you should use the ITX.. value, but when measuring the radio alone it is the I0dBm number that is relevant.

Best regards
Torbjørn