LT1521CST-3.3#TRPBF

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The LT1521CST-3.3#TRPBF is a 300mA low dropout regulator with micropower quiescent current and shutdown, manufactured by Analog Devices Inc. It provides a fixed 3.3V output in an SOT-223-3 package. The device operates with a typical dropout voltage of 0.5V at full load and maintains controlled quiescent current during dropout conditions. It features reverse battery protection and requires only a minimum 1.5µF output capacitor for stability.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Micropower operation with 12mA quiescent current and 6mA shutdown current
• Reverse input and output protection without external diodes
• Stable with small ceramic output capacitors starting at 1.5µF
• Kelvin sense capability for remote regulation compensation

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• Battery-powered systems requiring extended life
• Backup power situations with reversed or low input voltages
• Post-regulation for switching supplies
• Low current regulator circuits

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the specific ordering suffix #TRPBF indicates tape and reel packaging and lead-free compliance. Confirm the ST package designation matches the required SOT-223-3 footprint. Ensure the -3.3 suffix corresponds to the fixed 3.3V output requirement. Check for RoHS and REACH compliance documentation from the manufacturer.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this component when a fixed 3.3V output is needed with minimal standby current consumption. The SOT-223-3 package suits surface mount applications with moderate thermal requirements. Consider the 300mA current limit and 0.5V dropout characteristics against the system's maximum load and minimum input voltage constraints.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

This part belongs to the LT1521 series of low dropout regulators designed for battery-powered applications. The series includes adjustable and fixed voltage variants available in S8, MS8, and ST packages. The LT1521 family emphasizes low quiescent current that remains stable even under dropout conditions, distinguishing it from many other PNP-based LDOs.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

LT1521CST-3.3#PBF (Tube version)

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators FAQ

How does the LT1521 handle reverse input voltages?

The device withstands reverse voltages on the input pin up to 20V. In such cases, it acts as if there is a diode in series with its input, preventing reverse current flow into the device and protecting both itself and the load.

What is the minimum output capacitance required?

A minimum output capacitor of 1.5µF is required to prevent oscillations. Larger values may be necessary to handle larger load transients effectively.