7.4.5 Automatic Restart (Figure 17)

The TPS2491 automatically initiates a restart after a fault has caused it to turn off Q1. Internal control circuits use C_T to count 16 cycles before re-enabling Q1. This sequence repeats if the fault persists. The TIMER has a 1:10 charge-to-discharge current ratio, and uses a 1-V lower threshold. The fault-retry duty cycle specification quantifies this behavior. This small duty cycle often reduces the average short-circuit power dissipation to levels associated with normal operation and eliminates special thermal considerations for surviving a prolonged output short.

Figure 17. TPS2491 Restart Cycle Timing