2 Replies Latest reply on Aug 3, 2020 5:07 AM by LePo_1062026

    Voltage regulator and battery

    saga_1136906

      Hi all,

      I have a circuit that uses a battery type NCR18650PF with the relative charger mounted on breakout 03962A which uses the 4056E regulator.

      I have to supply a CYBLE-012011-00 type module. I was thinking of two solutions.

      The first: put the 03962A output, between out + and out-, a low consumption linear regulator, let's say 1.8V output. In this case I would have a current consumption as well as additional components to add.

      Second solution: supply the CYBLE module directly between out + and out-, since the charging voltages are within the tolerance limits of the module. So I would have the advantage of not having added current consumption and components.

      Can anyone give me some opinion?

       

      Thank you!

        • 1. Re: Voltage regulator and battery
          VasanthR_91

          Hi Savio,

           

          I was not exactly clear about what is the difference between the two options ? Are you planning to avoid the regulator in the second case ? If that is the case, having the regulator could be helpful for applications where a constant supply is critical( may be an ADC using VDD as reference). Also isolation and protection will also come in picture. If the specs are within the device tolerance, you can use it directly too.

           

          Best Regards,
          Vasanth

          • 2. Re: Voltage regulator and battery
            LePo_1062026

            saga,

             

            I don't understand why you don't drive the CYBLE-012011-00 directly from the battery.  The part is capable all the way to VDD=5.5V.

            If you want to supply 1.8V it sounds like you will need a LDO analog VREG as an output.  Sadly as you pointed out, there is current consumption usually in the range of 1 to 20 uA even if the CYBLE-012011-00 is in low power mode.

             

            I think you would be more power efficient running the CYBLE-012011-00 at about 5V nominal (during charging the NCR18650PF might see 4.4V).  At VDD=5V, the CYBLE-012011-00 in very low power mode should be > 10uA.  Besides starting with a higher VDD allows you to set a Brownout voltage detect to a reasonable value to allow you to shutdown better should you need to.

             

            Len