2 Replies Latest reply on Oct 3, 2019 7:01 PM by user_4464336

    Murata Type 1MW / CYW43455 LPO_IN clock

    user_4464336

      Hi Team,

       

      We are using the Murata Type 1MW module in a portable application and want to make use of the low-power Bluetooth sleep modes.
      In our application we have an always-on 1.8 V rail and 3.0-4.35 V supply provided by a single-cell Li-Po battery.

       

      My question pertains to the electrical properties of the 32.768 kHz external sleep clock (LPO_IN).

      Given that we have a 1.8 V supply available, it would be much easier to produce a 1.8 Vp-p 32.768 kHz clock signal for the module.

       

      In the technical documents section of the CYW43455 product information page on the cypress website, the application note AN214843 is referenced.
      In this application note, it suggests that a 1.8 Vp-p clock would be preferable from a power consumption perspective, but a 3.3 Vp-p would also be acceptable.
      While this application note does not reference the CYW43455 explicitly, I am wondering if this specification still applies to our chipset.

      Both the CYW43455 datasheet, and the Murata Type 1MW simply state that for the external LPO clock, a 200-3300 mVp-p signal is required.
      Does this requirement refer to a range of acceptable signal amplitudes? I.e. a 1800 mVp-p signal would be acceptable?

       

      Thanks in advanced,

      Cameron

        • 1. Re: Murata Type 1MW / CYW43455 LPO_IN clock
          MuraliR_36

          Hi

           

          Could you let us know as to where you found the reference in the 43455 section?

          But as mentioned in the introduction section of AN214843, this application note is for CYW2046, CYW4325, and CYW4329.

           

          ->Does this requirement refer to a range of acceptable signal amplitudes? I.e. a 1800 mVp-p signal would be acceptable?

          Yes, it specifies the range of acceptable signal amplitudes and 1800mVp-p should be acceptable.

          1 of 1 people found this helpful
          • 2. Re: Murata Type 1MW / CYW43455 LPO_IN clock
            user_4464336

            Hi MuraliR_36,

             

            As I mentioned above, the application note AN214843 does not explicitly mention the CYW43455 chipset.
            However, in the technical document section on the CYW43455 production information page, the application note is linked in.

            See the screenshot in my question above for the linked documents at the time of the question, or visit https://www.cypress.com/part/cyw43455xkubgt#technical-documents for the live product page.

             

            Thank you for answering that question, I will implement a 1800 mVp-p clock in the design.

             

            Regards,
            Cameron