L99LD21Q6

Overview

The L99LD21Q6TR is a high-power LED driver IC designed for automotive front lighting applications. It integrates a boost controller and dual buck converters to control two independent high-brightness LED strings. The device operates with an input voltage range of 5.5V to 24V and supports output voltages up to 50V. It features internal switching MOSFETs, peak current mode control, and PWM dimming with 10-bit resolution. The component is AEC-Q100 qualified and housed in a 40-QFN (6x6) package.

Feature Summary

• Integrates a high-efficiency monolithic boost controller and dual buck converters for flexible LED string control
• Features lossless current sensing without external components and accurate LED current programming via SPI
• Includes integrated PWM generation unit with 10-bit resolution and phase shift capabilities
• Provides comprehensive protection including overvoltage, short circuit, open load, and overtemperature shutdown

Applications

• Automotive front lighting systems
• High-brightness LED headlight control
• Dual-phase high-power LED applications

Procurement Notes

Verify the specific suffix Q6TR against the official datasheet to confirm package type and tape-and-reel specifications. Confirm AEC-Q100 qualification status and operating temperature range requirements match the target application environment. Check for any recent Product Change Notifications regarding assembly or material changes before finalizing procurement.

Selection Notes

Select this component when designing automotive lighting systems requiring independent control of two LED channels with integrated power stages. Ensure the design accommodates the 40-QFN package thermal requirements and utilizes SPI communication for configuration. Consider the 5.5V to 24V input range compatibility with standard automotive battery architectures.

Part Context

The L99LD21 series belongs to STMicroelectronics' portfolio of high-power LED drivers specifically engineered for automotive applications. It serves as a derivative of the L99LD20, adding a boost controller to support higher voltage LED strings. The family is characterized by its flexibility in handling various converter topologies and robust diagnostic features for safety-critical environments.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult the manufacturer's official obsolescence notices or cross-reference guides for potential alternatives if the L99LD21Q6TR becomes unavailable.