WSON (DRG)-8-9 mm² 3 x 3

The TPS22949 and TPS22949A are devices that provide protection to systems and loads in high-current conditions. The device contains a 500-mΩ current-limited P-channel MOSFET that can operate over an input voltage range of 1.62 V to 4.5 V as well as a low-dropout (LDO) regulator with a fixed output voltage of 1.8 V.

The switch is controlled by an on/off input (EN1), which can interface directly with low-voltage control signals. When the switch current reaches the maximum limit, the TPS22949/TPS22949A operates in a constant-current mode to prohibit excessive currents from causing damage. If the constant current condition persists after 12 ms, these devices shut off the switch and pull the fault signal pin (OC) low. The TPS22949/TPS22949A has an auto-restart feature that turns the switch on again after 70 ms if the EN1 pin is still active.

The output of the current limiter is internally connected to an RF low-dropout (LDO) regulator that offers good AC performance with very low ground current, good power supply rejection ratio (PSRR), low noise, fast start-up, and excellent line and load transient response. The output of the regulator is stable with ceramic capacitors. This LDO uses a precision voltage reference and feedback loop to achieve overall accuracy of 2% over all load, line, process, and temperature variations.

The TPS22949A integrates additional internal circuitry that increases the current limit of the switch during the power-up sequence. This feature allows the TPS22949A to operate without a storage capacitor at the input of the LDO.

The TPS22949 and TPS22949A are available in a space-saving 8-terminal WCSP (YZP) or in an 8-pin WSON package (DRG). Both devices are characterized for operation over the free-air temperature range of –40°C to 85°C.