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L138 LCDK RTC battery

Hi,

I'd like to ask question regarding L138 LCDK. PCB includes unpopulated position for battery holder, BH1. Please, can you provide me with information about type of this part? I'm unable to find this information in BOM. Thank you.

Best regards,

Martin

  • Hello Martin,

    The BH1 is a place holder for RTC battery. For the benefit of low cost, the L138 LCDK is not populated with this battery and the RTC_CVDD voltage rail is tied with CVDD rail.

    Since the LCDK design is not intended for battery backed RTC, we did not listed the battery part in the BOM.

    If you want to populate the battery for BH1, please ensure the voltage rating of RTC_CVDD rail mentioned in device datasheet.

    A battery from Panasonic with part number MT616 (Voltage=1.5V) is used in one of our older design. Also note that the battery circuit is provided with voltage divider to source 1.2V for RTC_CVDD.

    Unfortunately, the LCDK board doesn't have the battery circuit with voltage divider. So if you want to populate a battery, you must need to select a one with proper voltage rating.

    Regards,

    Senthil

  • Hello Senthil,

    thank you, this answers my question.

    Best regards,

    Martin