Nordic nRF52840 Thermal Characteristics

[Engineer]

Hi Nordic,

I’m H/W engineer, dedicated in development of radio circuit. I ask the question because we’d like propose your Nordice nRF52840 to our customer when replying the request of a BLE radio. So far we check the solution with the capability, much higher transmitting power than our usual solution, so it looks good but we found it better to estimate the generate heat and associated thermal effect soon because of that also. – That means we’d better starting the thermal works to prevent it becoming a matter with violation of thermal

Unfortunately, we can’t find the appropriate information (thermal resistance, maximum junction temperature). Could you let us have these information soon not mentioned to help of circuit integration happened to an AP. It’s looked forward to getting your feedback soon

[Turbo J]

Theta j-a highly depends on your board layout, and if it is 2, 4 or more layers.

I did not find anything for the AQFN73 package, but figures for regular QFN 7x7mm are in the 33-50°C/W range for Theta j-a.

But just looking at the current consumtion figures reval this as a non-issue. I strugge to get anything above 25mA consumtion for the entire chip, which yields less than 0.1W heat - or about 5 degress celsius over ambient.

Unless you do something crazy like shorting many output pins, the genereated heat will not be a problem.

[Engineer]

Thanks. It's a great comment. I shoud not concern too much when running thermal simulation if I target on the temperature of PCB less than 85C.