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The TPS71Hxx integrated circuits are a family of micropower low-dropout (LDO) voltage regulators. An order of magnitude reduction in dropout voltage and quiescent current over conventional LDO performance is achieved by replacing the typical pnp pass transistor with a PMOS device.

Because the PMOS device behaves as a low-value resistor, the dropout voltage is very low (maximum of 32 mV at an output current of 100 mA for the TPS71H50) and is directly proportional to the output current (see Figure 1). Additionally, since the PMOS pass element is a voltage-driven device, the quiescent current is very low and remains independent of output loading (typically 285 uA over the full range of output current, 0 mA to 500 mA). These two key specifications yield a significant improvement in operating life for battery-powered systems. The LDO family also features a sleep mode; applying a TTL high signal to EN (enable) shuts down the regulator, reducing the quiescent current to 0.5 uA maximum at T_J = 25°C.

Power good (PG) reports low output voltage and can be used to implement a power-on reset or a low-battery indicator.

The TPS71Hxx is offered in 3.3-V, 4.85-V, and 5-V fixed-voltage versions and in an adjustable version (programmable over the range of 1.2 V to 9.75 V). Output voltage tolerance is specified as a maximum of 2% over line, load, and temperature ranges (3% for adjustable version). The TPS71Hxx family is available in a TSSOP (20-pin) thermally enhanced surface-mount power package. The package has an innovative thermal pad that, when soldered to the printed-wiring board (PWB), enables the device to dissipate several watts of power (see Thermal Information section). Maximum height of the package is 1.2 mm.