2 Replies Latest reply on Jan 18, 2016 2:02 PM by userc_39669

    BLE Radio Current Profile



      I'm trying to characterize power consumption on the CY8CKIT-042 BLE kit and compare performance against Nordic nRF51 and nRF52 for BLE radio events.


      Does Cypress have BLE current profile for connection and advertising event?  Nordic provides this data in the datasheet/product specification and Softdevice specification.  I checked the PSoC_4_PSoC_4XX7_BLE datasheet and TRM and could not find the data.  Do you guys have this internally and could share?


      The application note "Designing for Low Power and Estimating Battery Life for BLE Applications" provides some reference but leaves a bit to be desired.  Figure 9 and 10 are oscilloscope captures for advertising and connection event with sub time-periods referenced as alpha terms.  Figure 21 and 23 are cartoon diagrams showing the different BLE radio modes and also if the Cortex M0 is active.


      If I could have this figure with rough time periods for each mode and expected current consumption that would be great.


      Attached figure of what I'm looking for here:






      Thank you,

        • 1. Re: BLE Radio Current Profile

          Designing for Low Power and Estimating Battery Life for BLE Applications provides average current for both advertisement and connection event. Isn't that sufficient?

          • 2. Re: BLE Radio Current Profile

            @Undesh: Thank you for the response.


            The application note mentioned 'Designing for Low Power and Estimating Battery Life for BLE Applications' provides an excel macro sheet which estimates average current given IMO frequency, crystal tolerances, and advertising or connection interval.  The PDF includes a measured oscilloscope cursor trace (Figure 9/10) which shows the time length of the BLE event.  


            I still don't see a piecewise reference like what Nordic provides with expected current and time length.  I do not understand stage reference provided in this document in Table 14 'A-J' as it does not match with the reference Figure 9.  


            I've measured a 5.61msec packet with 7.09mA draw for advertising.  And a 3.13msec packet with 4.56mA draw for connection.  These roughly compare to what the excel macro sheet provides of 41 and 15.6 uA respectively for advertising and connection events but a much larger error exists between expected and measured as compared to the Nordic nRF51 comparison.  


            Is it best to file a request with Cypress Application Engineers for this information?


            Some other questions that are relevant to this discussion:
            1) Does effective ON-time of MCU during BLE advertising or connection event vary with changing IMO clock frequency?