Relation of power consumption and temperature nRF51822

[MRF]

Hello,

I am using a RFDigital Simblee module (nRF51822 chip) and an ADC with thermocouples to measure high temperatures and process the temperature data via BLE. So I'm using it like a wireless temperature sensor module.

Now the ambient temperature of the chip in this application is mostly < 85°C, but sometimes reaches up to 120°C. Everything works fine, but I noticed that the power consumption increases dramatically ( x 40 ) with higher temperatures. I tested it without the ADC and it seems that the qC is responsible for that.

My question is: Do you have got any more Information or diagrams about the relation of power consumption and temperature with these chips?

Looking Forward to your answer, sorry for my bad english. Greetings, M. Fock

[Sigurd]

Hi,

The max operating temperature of the nRF51822 is 75 °C. (See page 39 in the PS). Exposure to temperatures above the max ratings is not recommend, and various things will be outside specification, such as the current consumption. The radio and other peripherals might not work either if they are exposed to temperatures above the max ratings.

I recommend that you switch to the nRF51824, which is auto grade AEC-Q100 qualified(Grade 2: -40 to 105ºC).

[awneil]

Quite a well known rule of thumb is that leakage current in semiconductors doubles with each 10 C increase.

There are many other factors, too: www.springer.com/.../9781461407478-c1.pdf

This is why all semiconductor manufacturers - including Nordic - specify a maximum operating temperature for their devices. If you exceed this (or any other) limit, then the device will not operate within its specifications.