L99LD01TR-E

Overview

The L99LD01TR-E is a precise constant current DC-DC converter LED driver for automotive applications, housed in a 32-pin LQFP package. It supports Boost, Buck-Boost, and Flyback topologies with an internal random dither oscillator for EMC reduction. Key parameters include a regulated 5V microcontroller supply output at ±2% accuracy with up to 20mA capability. The device features adjustable switching frequency via external resistor RSF and slope compensation via R9. Battery overvoltage shutdown requires external resistors R3 and R4, while LED chain overvoltage detection uses R5 and R6.

Feature Summary

• Integrates an internal random dither oscillator operating in low frequency modulation to spread the RF spectrum of the switching frequency, thereby reducing electromagnetic compatibility emissions.
• Provides slope compensation to ensure stable converter loop performance across varying duty cycles required by specific application designs.
• Includes an internal low-drop voltage regulator capable of supplying a microcontroller, accompanied by a reset pin for startup initialization and undervoltage threshold monitoring.

Applications

• Control of high-brightness LED headlights in automotive environments
• Boost converter topology implementations for LED string driving
• Buck-Boost converter configurations for variable input voltage scenarios

Procurement Notes

Verify the specific suffix 'E' against the manufacturer's official documentation to confirm compliance with environmental directives and material specifications. Ensure the ordering part number matches the exact package type and tape-and-reel configuration required for your assembly process. Cross-reference the datasheet revision date to guarantee alignment with current design-in requirements and available support resources.

Selection Notes

Select this component when designing automotive lighting systems requiring precise constant current regulation within Boost, Buck-Boost, or Flyback topologies. Consider the integrated EMC reduction features if strict electromagnetic emission limits are mandated. Evaluate the need for external sensing resistors for current setting and the availability of external components for protection thresholds like battery overvoltage shutdown.

Part Context

This part belongs to the L99LD series of high-power LED drivers designed specifically for automotive front lighting applications. It represents a monolithic solution combining control logic with power stage management, distinguishing it from general-purpose DC-DC converters by its specialized focus on LED string stability and automotive-grade reliability standards.

Replacement Considerations

Consult official STMicroelectronics substitution guides for verified alternatives. No direct public substitute part numbers are confirmed in the provided source data. Verify pinout and thermal compatibility if considering cross-brand options.