SLVS736C February 2008 – October 2023 TPS2550 , TPS2551
PRODUCTION DATA
Some applications require that an overcurrent condition disables the part momentarily during a fault condition and re-enables after a pre-set time. This auto-retry functionality can be implemented with an external resistor and capacitor. During a fault condition, FAULT pulls low disabling the part. The part is disabled when EN is pulled low, and FAULT goes high impedance allowing CRETRY to begin charging. The part re-enables when the voltage on EN reaches the turnon threshold, and the auto-retry time is determined by the resistor/capacitor time constant. The part continues to cycle in this manner until the fault condition is removed.
Some applications require auto-retry functionality and the ability to enable/disable with an external logic signal. The figure below shows how an external logic signal can drive EN through RFAULT and maintain auto-retry functionality. The resistor/capacitor time constant determines the auto-retry time-out period.