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LM25148-Q1: BOOT UVLO operation

Part Number: LM25148-Q1

Hello support team,

Please tell me about the operation when BOOT UVLO is detected. (VBOOT-SW drops to 2.5V)

What if the VIN is low and VBOOT-SW does not recover to 2.7V?


  • Hi Kiyoshi,

    When Boot UVLO is detected the controller shuts of HO drive high side MOSFET.

    After multiple failures of turning on highside, the device should turn on lowside for a short time for boot recharge.

    Note at low-VIN and low-VCC, the boot capacitor will instantly drain charge from VCC capacitor, so the VCC voltage can drop quickly when recharging the boot capacitor.

    A boot refresh at low VIN might drain VCC cap to VCC UVLO.