LT1117CST#PBF

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

The LT1117CST#PBF is a positive low dropout regulator manufactured by Analog Devices Inc., housed in a 3-lead plastic SOT-223 package. It provides up to 800mA of output current with guaranteed dropout voltage at multiple current levels, operating down to 1V input-to-output differential. The device features on-chip trimming for reference and current limit to minimize stress during overload conditions. Quiescent current flows into the load rather than being wasted, enhancing efficiency compared to PNP-type regulators. Stability requires a minimum of 10μF output capacitance.

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

• Low profile surface mount SOT-223 package designed for space-limited applications
• Internal circuitry operates down to 1V input to output differential
• Quiescent current flows into the load to increase overall efficiency
• On-chip trimming adjusts reference voltage and limits current under overload

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

• Active SCSI Terminators
• High Efficiency Linear Regulators
• Post Regulators for Switching Supplies
• Battery Chargers
• 5V to 3.3V Linear Regulators

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

Verify the specific ordering suffix against official documentation to confirm lead-free finish status and tape-and-reel availability. Confirm that the ST package designation matches the required surface-mount footprint. Ensure the component grade aligns with the intended operating temperature range requirements for the target application environment.

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

Select this regulator when space constraints necessitate a low-profile SOT-223 package while requiring high current capability. It is suitable for designs needing efficient linear regulation where quiescent current waste must be minimized. Ensure the application includes adequate output capacitance for stability and considers thermal dissipation capabilities of the PCB layout for continuous operation.

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

This component belongs to the LT1117 family of 800mA low dropout positive regulators from Analog Devices. The family includes adjustable versions and fixed output variants such as 2.85V, 3.3V, and 5V. The LT1117CST#PBF specifically denotes the commercial grade version in the SOT-223 package, distinct from the industrial grade or DD-Pak package alternatives within the same product line.

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

LT1117IST#PBF (Industrial Grade, SOT-223)

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

What is the minimum output capacitance required for stability?

A minimum of 10μF of tantalum or 50μF of aluminum electrolytic capacitor is required for stability.

How does the quiescent current behavior differ from PNP regulators?

Unlike PNP regulators where quiescent current is wasted, the LT1117's quiescent current flows into the load, thereby increasing efficiency.