The TPS71025 low-dropout regulator offers an order of magnitude reduction in both dropout voltage and quiescent current over conventional LDO performance. The improvement results from 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 95mV at an output current of 100 mA) 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 292 uA over the full range of output current, 0 mA to 500mA). These two key specifications yield a significant improvement in operating life for battery-powered systems.