LT1121 LT1121CS8 LT1121CS8-3 LT1121CS8-3.3 LT1121CS8-5 - Micropower Low Dropout Regulators with Shutdown

Features and Benefits

• 0.4V Dropout Voltage
• 150mA Output Current
• 30μA Quiescent Current
• No Protection Diodes Needed
• Adjustable Output from 3.75V to 30V
• 3.3V and 5V Fixed Output Voltages
• Controlled Quiescent Current in Dropout
• Shutdown
• 16μA Quiescent Current in Shutdown
• Stable with 0.33μF Output Capacitor
• Reverse Battery Protection
• No Reverse Current with Input Low
• Thermal Limiting
• Available in the 8-Lead SO, 8-Lead PDIP, 3-Lead SOT-23 and 3-Lead TO-92 Packages

Product details

The LT1121/LT1121-3.3/LT1121-5 are micropower low dropout regulators with shutdown. These devices are capable of supplying 150mA of output current with a dropout voltage of 0.4V. Designed for use in battery-powered systems, the low quiescent current, 30μA operating and 16μA 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 LT1121/LT1121-3.3/LT1121-5 include the ability to operate with very small output capacitors. They are stable with only 0.33μF on the output while most older devices require between 1μF and 100μF for stability. Small ceramic capacitors can be used, enhancing manufacturability. Also the input may be connected to ground or a reverse voltage without reverse current flow from output to input. This makes the LT1121 series ideal for backup power situationswhere the output is held high and the input is at ground or reversed. Under these conditions only 16μA will flow from the output pin to ground.

Applications

• Low Current Regulator
• Regulator for Battery-Powered Systems
• Post Regulator for Switching Supplies