LT1121AHVIS8

peculiarity

• 0.4V dropout voltage
• 150mA output current
• 30μA quiescent current
• No protection diodes are required
• Adjustable output range from 3.75V to 30V
• Fixed 3.3V and 5V output voltages
• Controlled quiescent current under dropout conditions
• Shutdown function
• Quiescent current in shutdown: 16μA
• Stable with a 0.33μF output capacitor
• Reverse battery protection
• No reverse current at low inputs
• Thermal limiting
• Available in 8-lead SO, 8-lead PDIP, 3-lead SOT-23, and 3-lead TO-92 packages

description

LT^® The 1121/LT1121-3.3/LT1121-5 are micropower low dropout regulators with shutdown. These devices are capable of delivering 150mA of output current with a dropout voltage of 0.4V. They are designed for use in battery-powered systems, and their low quiescent current (30μA during operation and 16μA in shutdown) make them an ideal choice. Quiescent current is well controlled; Quiescent current does not rise under dropout conditions, unlike many other low-dropout PNP regulators.

Other features of the LT1121/LT1121-3.3/LT1121-5 include the ability to operate with very small output capacitors. They are stable with only 0.33μF capacitors laid out on the output, whereas most older devices require 1μF to 100μF output capacitors for stabilization. Manufacturability is enhanced by the ability to use small ceramic capacitors. In addition, the input can be connected to ground or a reverse voltage without generating reverse current from the output to the input. This makes the LT1121 family ideal for standby supplies where the output is held high and the input is at ground or reversed. Under these conditions, the current flowing from the output pin to ground will be only 16μA.