Max Power consumption for nRF51824

[TNeagoe]

Hello there, I need to specify the LDO that will power the nRF51824. What would be the max current consumption for nRF51824 at 3.3V? I saw a similar calculation for 51822 but I would need one for 51824. Teodor

[AmbystomaLabs]

All nRF devices have their power consumption for all scenarios listed in their spec. All these devices are half duplex and thus cannot both transmit and receive simultaneously. Just take your intended use scenario, add in your gpio usage (eg, i2c, uarts, leds, etc.) and voila!

Though I would say more important is the power dissipation from your LDO. I don't know why you chose an LDO instead of buck converter but you need to make sure the package will handle the VI heat output depending on your input voltage and operating temp range. Some of the smaller wlcsp LDO's have pretty minuscule power handling.

[TNeagoe]

Thank you for your fast answer. However datasheets shows 13 mA peak RX, 10.5 mA peak TX (0 dBm). What would be the peak TX current at 4dBm? I was thinking of using an LDO for lower noise. 13mA x 1.7V = 22.1mW; not much to dissipate.

[AmbystomaLabs]

Not sure what spec you are looking at but page 42 of the 51824 product spec clearly shows the tx current as 11.8mA at +4dBm or if you really want to waste power you can run it with the DC/DC off and then you can get to to draw 16mA.

But you seriously need to add in gpio. People throw all kinds of things on the gpio that shouldn't be there and it adds up. A common mistake is having gpio source LED's instead of sinking them.

Here is the spec: infocenter.nordicsemi.com/.../nRF51824_PS_v1.0.pdf