The TPS72xx family of low-dropout (LDO) voltage regulators offers the benefits of low-dropout voltage, micropower operation, and miniaturized packaging. These regulators feature extremely low dropout voltages and quiescent currents compared to conventional LDO regulators. Offered in small-outline integrated-circuit (SOIC) packages and 8-terminal thin shrink small-outline (TSSOP), the TPS72xx series devices are ideal for cost-sensitive designs and for designs where board space is at a premium.
A combination of new circuit design and process innovation has enabled the usual pnp pass transistor to be replaced by a PMOS device. Because the PMOS pass element behaves as a low-value resistor, the dropout voltage is very low - maximum of 85 mV at 100 mA of load current (TPS7250) - and is directly proportional to the load current (see Figure 1). Since the PMOS pass element is a voltage-driven device, the quiescent current is very low (300 uA maximum) and is stable over the entire range of output load current (0 mA to 250 mA). Intended for use in portable systems such as laptops and cellular phones, the low-dropout voltage and micropower operation result in a significant increase in system battery operating life.
The TPS72xx also features a logic-enabled sleep mode to shut down the regulator, reducing quiescent current to 0.5 uA maximum at TJ = 25°C. Other features include a power-good function that reports low output voltage and may be used to implement a power-on reset or a low-battery indicator.
The TPS72xx is offered in 2.5-V, 3-V, 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).