The TPS797xx family of low-dropout voltage regulators (LDOs) offers the benefits of low-dropout voltage and ultra-low-power operation. The device is stable with any capacitor greater than 0.47-µF. Therefore, implementations of this device require very little board space due to the miniaturized packaging and potentially small output capacitor. In addition, the family includes an integrated open drain active-high power good (PG) output. Intended for use in microcontroller-based, battery-powered applications, the TPS797xx family low dropout and ultra-low-power operation result in a significant increase in system battery operating life. The small packaging minimizes consumption of board space.
The device is enabled when the applied voltage exceeds the minimum input voltage. The usual PNP pass transistor has been replaced by a PMOS pass element. Because the PMOS pass element behaves as a low-value resistor, the dropout voltage is very low (typically, 105 mV at 10-mA of load current), and is directly proportional to the load current. The quiescent current is ultra-low (1.2-µA, typically) and is stable over the entire range of output load current (0 mA to 50 mA). When properly configured with a pullup resistor, the PG output can implement a power-on reset or low-battery indicator.