nRF52 current consumption in relation to supply voltage

[MatthiasW]

Hello,

in the Online Power Profiler, the current consumption increases, when the voltage is reduced. What is the reason for this?

Isn't there any documentation on the power consumption in relation to the supply voltage, with LDO or DCDC?

[AmbystomaLabs]

It just basic ohm's law. When you utilize a dc/dc converter it is simply converting power at one voltage to power at another voltage.

Since power = volts x amps then when you reduce the input voltage the current must increase for the power output to be the same.

Or you can show the relation as (Vout/Vin) x I out = I in.   So the ratio of output voltage to input voltage times the output current is the input current.

There are some minor changes to this due to the dc/dc regulator efficiency. But this is best to get the concept across.

With an LDO it is a different story since amps out is equal to amps in. No matter what the input voltage is the input current is always the output current.  This is why an LDO is very inefficient since the difference in power between input and output is given off as heat in the LDO.