LT1521-5 Datasheet | Linear Technology

LT1521/LT1521-3 LT1521-3.3/LT1521-5 300m A Low Dropout Regulators with Micropower Quiescent Current and Shutdown Features s s s s s s s s s s s DESCRIPTION The LT ®1521/LT1521-3/LT1521-3.3/LT1521-5 are low dropout regulators with micropower quiescent current and shutdown. These devices are capable of supplying 300m A of output current with a dropout voltage of 0.5V. Designed for use in battery-powered systems, the low quiescent current, 12 µA operating and 6 µA in shutdown, makes them an ideal choice. The quiescent current is well controlled; it does not rise in dropout as it does with many other low dropout PNP regulators. Other Features of the LT1521/LT1521-3/LT1521-3.3/ LT1521-5 include the ability to operate with very small output capacitors. They are stable with only 1.5µF on the output while most older devices require between 10µF and 100µF for stability. Small ceramic capacitors can be used, enhancing manufacturability. Also, the input may be connected to voltages lower than the output voltage, including negative voltages, without reverse current flow from output to input. This makes the LT1521 series ideal for backup power situations where the output is held high and the input is low or reversed. Under these conditions only 5µA will flow from the output pin to ground. , LTC and LT are registered trademarks of Linear Technology Corporation. Dropout Voltage: 0.5V Output Current: 300m A Quiescent Current: 12µA No Protection Diodes Needed Adjustable Output from 3.8V to 20V Fixed Output Voltages: 3V, 3.3V, 5V Controlled Quiescent Current in Dropout Shutdown IQ = 6µA Reverse Battery Protection No Reverse Current Thermal Limiting U APPLICATIONS s s s Low Current Regulator Regulator for Battery-Powered Systems Post Regulator for Switching Supplies TYPICAL APPLICATION 5V Battery-Powered Supply with Shutdown 8 1µF 5 SHDN GND 3 IN LT1521-5 SENSE 2 OUT 1 5V 300m A 0.6 0.5 DROPOUT VOLTAGE (V) + 6V 1.5µF 0.4 0.3 0.2 0.1 VSHDN (PIN 5) OUTPUT <0.25 OFF >2.80 ON NC...