POWER UP Circuit and RESET behaviour

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3 thoughts on “POWER UP Circuit and RESET behaviour”

  1. Greetings,

     

      We have developed a custom board to use the GC864QUADV2 as a "serial port"TO "GPRS" converter. We use a voltage monitoring IC to generate the ON Active low pulse (>1 seg and <2 seg). When there are voltage disturbances in the power network the sags produce temporal low voltage conditions in our power supply that when longer than 2 seconds cause the voltage supervisor to turn the modem off.

    This is quite rare but happens, I wonder if holding the modem in RESET during a

    low voltage condition (<3,4V ) is an accepted practice? I may be able to multiplex the

    voltage supervisor and direct the signal to the ON/OFF pin or the reset pin accordingly.

     

    Is there any App Note regarding the start-up circuit? We are thinking in changing the Voltage supervisor IC for a "watchdog+voltage supervisor"

     

    Best Regards,

     

    Haroldo Calvo

     

     

     

    1. From
      customer description it is difficult give an answer. In some similar
      cases the permanently connection of ON_OFF* pin to GND avoid the need to
      provide the ON pulse for turning on the module; in these cases the
      module is always in turned on status when the Power Supply voltage is
      applied to VBATT pins of the module. However for a better support the
      customer should contact directly ts-emea@telit.com providing us the
      schematic and further clarification about application requirements.

      Regarding
      holding the module in RESET during a low voltage condition, this isn’t a
      condition tested exhaustively from Telit so we aren’t able to assure
      the absence of contraindications.

      The official procedure tested exhaustively for turning on and off the module are thaose one present in HUG.