This content is written for hardware engineers and power supply designers.
The UPD pin (Update) is a key protection feature of the MP3378E. The UPD pin is used to report the status of the IC's protection mechanisms and to update the IC's internal registers. The UPD pin is an open-drain output that is pulled low when a protection event occurs. mp3378e protection pin upd
This often indicates the OVP is triggering. Check if an LED string is disconnected or if your OVP resistor divider is set too low for the required output voltage. This content is written for hardware engineers and
[ V_OUT(OVP) = 2.0V \times \left(1 + \fracR_TOPR_BOTTOM\right) ] The UPD pin is an open-drain output that
: If the voltage at the OVP pin exceeds a preset internal threshold, the IC shuts down the PWM generator and disables the MOSFET drivers to prevent thermal runaway or component damage. : This protects against open-circuit
