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usual PNP pass transistor has been replaced by a PMOS pass element.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.
