Texas Instruments Debuts New TPS78825 and TPS78833 LDOs
Texas Instruments (Dallas, TX) announced the new TPS78825 and TPS78833, low-noise LDOs for use in USB applications. Housed in SOT-23 packaging, the LDOs regulate the output voltage to 2.5V and 3.3V with input voltage ranging from 2.7V to an absolute maximum of 13.5V. These devices output 150mA with a peak current of 350mA.
The TPS788xx family uses the SR pin to program the output-voltage slew-rate to control the inrush current. This is specifically used in the USB application where large load capacitance is present at startup. The TPS788xx devices use only 17uA of quiescent current and exhibit only 56uV RMS of output-voltage noise using a 10uF output capacitor.
The usual PNP pass transistor in Texas Instruments' new devices has been replaced by a PMOS pass element. The PMOS pass element behaves as a low-value resistor; therefore, the dropout voltage is very low, typically 150mV at 150mA of load current, and is directly proportional to the load current. The TPS788xx also features a logic-enabled sleep mode to shut down the regulator, reducing quiescent current to 1uA at 25 degrees C.
