LDL1117S12R

Overview

The STMicroelectronics LDL1117S12R is a fixed-output low-dropout linear voltage regulator providing a stable 1.2 V output with a maximum guaranteed current of 1.2 A. It operates within an input voltage range of 2.5 V to 18 V and features a typical dropout voltage of 350 mV at full load. The device incorporates high power supply rejection ratio (PSRR) capabilities, reaching 87 dB at 120 Hz, making it suitable for noise-sensitive applications. Integrated protections include thermal shutdown, current limiting, and safe operating area (SOA) protection. It is housed in a compact SOT-223 package and supports operation across an extended temperature range from -40 °C to +125 °C.

Feature Summary

• Provides regulated 1.2 V output with up to 1.2 A continuous current capability
• Features high PSRR for effective noise suppression in power-sensitive circuits
• Includes comprehensive internal protections against overcurrent, overheating, and unsafe operating conditions

Applications

• Direct regulation in switch-mode power supply (SMPS) architectures
• Secondary linear regulation stages in DC-DC converter designs
• Power conditioning for noise-sensitive analog and digital subsystems

Procurement Notes

Verify the exact part marking and datasheet revision when sourcing. Confirm that the specific suffix matches the required package and temperature grade. Ensure compatibility with your board's thermal management strategy given the SOT-223 form factor. Cross-reference official documentation to validate pinout and electrical limits before finalizing procurement.

Selection Notes

Select this component when a stable 1.2 V rail is required with moderate current demands up to 1.2 A. It is appropriate for designs needing high ripple rejection without complex external filtering. Consider the thermal dissipation requirements in the SOT-223 package under maximum load conditions. Verify that the input voltage remains within the specified 2.5 V to 18 V window for proper regulation.

Part Context

This regulator belongs to the LDL1117 family of 1.2 A fixed LDO voltage regulators from STMicroelectronics. The series offers various fixed output voltages to suit different logic levels. The S12 variant specifically targets 1.2 V applications, commonly used in embedded systems requiring clean power for sensitive microcontrollers or peripheral interfaces.

Replacement Considerations

Check for direct equivalents within the same LDL1117 family offering identical 1.2 V output and SOT-223 packaging. Verify that any substitute maintains the 1.2 A current rating and similar thermal protection characteristics to ensure circuit reliability.