1 2 Previous Next 20 Replies Latest reply on Nov 10, 2014 9:46 AM by honh_2138766 Go to original post Branched to a new discussion.
      • 15. Re: BCM20736S Sleep Example Firmware

        I will ask the developers how to determine whether or not the part has entered into connected idle mode.


        Unfortunately, we do not have any internal power measurements taken with the chip in a connected state.

        • 16. Re: BCM20736S Sleep Example Firmware

          I wanted to check in and let you know that we are still escalating this internally with the Business Unit and trying to get some cycles from the development team to investigate.  Thanks for your patience.


          I do know that internally we have struggled to get accurate current consumption readings from the TAG3 because of ground plane issues.  In addition, the board does not use a DC-DC, so any measured value would be at least 50% lower than what's listed in the datasheet (the datasheet has a note to this effect as well).






          • 17. Re: BCM20736S Sleep Example Firmware

            Just an unsolicited comment.   If you are using linear regulators, current consumption won't go down if the input voltage to the regulator changes.  The amount of power (in watts) consumed will drop but the current remains the same.   A linear regulator burns whatever excess voltage as heat in the regulator and can be quite inefficient.



            The only way to truly reduce battery current is to use a switching regulator.  You have to be careful here because this can introduce switching noise on your power supply and this can play all kinds of evil games with radios or other linear circuits.  With current consumption in the 1-50 microamp range, switching regulators will probably still burn more power than the circuit it powers.

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            • 18. Re: BCM20736S Sleep Example Firmware

              This sounds really cool.

              Let me expand the day to 25 hours so that I can try it as well.  

              • 19. Re: BCM20736S Sleep Example Firmware

                Sure, an LDO burns the voltage difference. But if current goes down on load, the burning heat goes gown as well.

                Any optimization on load (current consumption) will help for longer battery capacity available.

                Sure, SPS is more efficient but I would assume a good design and using frequencies not as harmonics of other clocks, oscillators, RF ... can help. My five cents: SPS needs often inductors which result in higher BOM and more complicated PCB (LDO can be inside and very small).


                I think, he has spent his brain power to improve by better core sleep mode states. It sounds valuable and reasonable for me as (or do you expect we can change the silicon and the system design during this Hackathon?    )

                I appreciate his great achievement.

                • 20. Re: BCM20736S Sleep Example Firmware





                  At the center and further down the link, there are 3 or 4 tables showing battery life as a function of Tx power and "Connnection Interval". This is what I meant by power consumption in "Connected IDLE" mode in my problem report: WICED SMART datasheet has none of this, and worse, when I tried to measure it, it is much poorer than TI and Nordic chips.  Maybe this lack on info is why WICED is not used in any of these 16 leading vendors of iBeacons .  (Note: BlueGiga and Gimbal in this link also use TI BLE chips but they write their own low-level firmware for further optimization)

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