nRF52 Radio Performance and adaptive regulator control

[Dave_couling]

Why does the nRF52 only have +4dB output when most competitor chips are atleast +6dB (some up to +10dB). I understand that the RX has been improved by 3dB for a better overall link budget, but for beacon applications Tx rules. Is there any plan to release a higher power Tx version?

Looking over the new chip it seems the nRF52 has Adaptive Regulator Control. Does this mean it can smartly switch between internal LDO and external DCDC depending on current consumption?

Thanks,

DC

[wlgrd]

Have you actually tried getting 6/10db from these other chips? What's the current consumption?

[Dave_couling]

Yes,

+8dB out of the ST BlueNRG making it a good candidate for beacon applications (though higher in peak currents, the interval of beacon applications make this ok). Not suitable for actual connected applications and the Link budget of a connection isn't as good since there is an inferior TX.

+7.5dB on the CSR1011. Again much high peak currents, but these are older chips. I was hoping the new Nordic chip would have a comparable max Tx output for beacon applications.

+5dB CC2640 though in the fine print it looks to be only +2dB once put through a balun.

[wlgrd]

Thanks! I don't know much about radio, but could it be hard to maintain the low peak currents on radio while still have a large range of settings for output power?

[cocoa]

Laird Technologies has a documentated range test, using a nRF51, TI chip, iPhone and iPad.

Nordic reaches 128 mt line of sight , with an iPad 3.

Not bad, I think that a 128 mt range should be enough for an iBeacon.

This range was achieved using the old (dear) nRF51.

Look at the document : Laird Range Testing

-c

[Øyvind Karlsen]

Hi Dave,

For an energy efficient application, TX power is not key. A transmit power of 4dBm corresponds to 2.5mW, a transmit power of 10dBm corresponds to 10mW. While it's nice to have a lot of transmit power and a very high link budget you can't have it all in a low energy application. Usually the main requirement for your beacon is that it should last for a long time.

Note that to be compliant with BLE you need to have an EIRP(Effective Isotropic Radiated Power) of max 10mW. If you can achieve some of this through passive gain(e.g. antenna), that's great!

If you want to run proprietary you can still use a power amplifier, then you're just limited by the ISM-band power requirement.

There's a general trend in radio systems where you use lower TX power. High TX power was a workaround to achieve required range in the time before sensitive radios, think about old AM radio, e.g. radio Warsaw radio tower transmitting 2MW(63dB!).

Best regards,

Øyvind