The TPS22946 is an ultralow power load switch that provides protection to systems and
loads in high-current conditions. The device contains a 300-mΩ current-limited P-channel MOSFET
that can operate over an input voltage range of 1.62 V to 5.5 V. The switch is controlled by an
on/off input (ON), which can interface directly with low-voltage control signals. The TPS22946
includes thermal shutdown protection that prevents damage to the device when a continuous
over-current condition causes excessive heating by turning off the switch.
When the switch current reaches the maximum limit, the TPS22946 operates in a
constant-current mode to prohibit excessive currents from causing damage. The current limit can be
selected using the CL input: a high CL input sets the current limit to 155 mA, a low CL input sets
the current limit to 70 mA, and a floating CL input sets the current limit to 30 mA.
If the constant current condition persists after 10 ms, the switch is turned off and the
fault signal pin (OC) is pulled low. The TPS22946 has an auto-restart feature which turns the
switch on again after 70 ms if the ON pin is still active. If the TPS22946 remains in an
over-current condition for 5 seconds, the device shuts off until it is turned on again by setting
the ON control signal off and then on.
If the device is used to protect an LDO, the inrush current required by the LDO at
startup can, in some cases, exceed the current limit and initiate a blanking (current limiting)
condition. The TPS22946 provides allowance for this scenario during startup of the LDO by
temporarily increasing the current limit to 435 mA for 8 ms after the load switch is
The TPS22946 is available in space-saving 6-pin DSBGA (YZP) package. The device is
characterized for operation over the free-air temperature range of 40°C to 85°C.