Datasheet

TPS2492
TPS2493
www.ti.com SLUSA65C –JULY 2010–REVISED JANUARY 2013
Automatic Restart (Figure 18)
The TPS2493 automatically initiates a restart after a fault has caused it to turn off the external FET. Internal
control circuits use C
T
to count 16 cycles before re-enabling the external FET. This sequence repeats if the fault
persists. TIMER has a 1:10 charge-to-discharge current ratio, and uses a 1-V lower threshold. The fault-retry
duty cycle specification in the Electrical Characteristics Table quantifies this behavior. This small duty cycle often
reduces the average short-circuit power dissipation to levels associated with normal operation and reduces the
need for additional measures such as oversized heatsinking. Figure 18 demonstrates that the initial timing cycle
starts with V
TIMER
at zero V, subsequent cycles start with V
TIMER
at 1 V, and a succesful restart occurs after a 16
cycle delay.
Figure 18. TPS2492/93 Restart Cycle Timing
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