Datasheet

TPS22946
SLVS984A –SEPTEMBER 2009–REVISED FEBRUARY 2010 www.ti.com
Current Limiting Mode
When an over-current condition (moderate or a hard short) is detected, the TPS22946 operates in a
constant-current mode to prohibit excessive currents from causing damage. TPS22946 has a current limit of
30 mA, 70 mA or 155 mA.
If the constant current condition still persists after 10ms, the device shuts off the switch and pulls the fault signal
pin (OC) low. The TPS22946 has an auto-restart feature which turns the switch on again after 70 ms if the ON
pin is still active.
Fault Reporting
When a moderate over-current, hard short or over-temperature condition is detected, OC is set active low to
signal a fault condition. OC is an open-drain MOSFET and requires a pullup resistor between V
IN
and OC. During
shutdown, the pulldown on OC is disabled, reducing current draw from the supply.
Power-On / Power-Off Sequence
The device is enabled internally only once the hard-short detection circuit is enabled.
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