JAJSEL2D January 2018 – December 2019 TPS25221
PRODUCTION DATA.
Some applications require that an over-current 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 turn-on threshold, and the auto-retry time is determined by the resistor-capacitor time constant. The device continues to cycle in this manner until the fault condition is removed.
Some applications require auto-retry functionality and the ability to enable or disable with an external logic signal. Figure 28 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.