L99LD21Q6TR

Overview

The L99LD21Q6TR is a flexible LED driver IC designed for automotive front lighting applications, featuring two independent high-brightness LED string controls. It integrates a high-efficiency monolithic boost controller and dual buck converters. The device operates within a battery voltage range of 5.5V to 24V and supports output voltages up to 50V with an output current of 1.5A per channel. It utilizes PWM dimming with a frequency range of 100kHz to 450kHz. The component is AEC-Q100 qualified and housed in a 40-QFN (6x6) package.

Feature Summary

• Integrates a high-efficiency boost controller with an external n-channel MOSFET gate driver and dual buck converters with integrated switching MOSFETs.
• Supports dual-phase operation for interleaved input current ripple improvement in high-power applications.
• Features lossless current sensing without external components and accurate LED current setting via SPI-adjustable peak current and ripple.
• Includes comprehensive protection mechanisms such as overvoltage, short circuit, open load, and overtemperature shutdown.

Applications

• Automotive front lighting systems
• High-brightness LED string control
• Dual-phase high-power LED drivers

Procurement Notes

Verify the specific suffix Q6TR against the manufacturer's official datasheet to confirm package type and tape-and-reel specifications. Ensure compatibility with the required automotive qualification standards, specifically AEC-Q100, before integration. Confirm that the 40-QFN footprint matches the design layout. Check for any recent Product Change Notifications regarding assembly or material changes.

Selection Notes

Select this component when designing automotive front lighting requiring independent control of two LED strings with high efficiency. It is suitable for applications needing both boost and buck topologies within a single IC. Consider its AEC-Q100 qualification for automotive reliability requirements. Evaluate the need for dual-phase operation if input current ripple reduction is critical for the system.

Part Context

The L99LD21 belongs to STMicroelectronics' family of high-power LED drivers for automotive applications. It is derived from the L99LD20 but adds a monolithic boost controller, enabling higher voltage LED string configurations. This integration allows for more compact designs compared to using separate boost and buck controllers.

Replacement Considerations

The L99LD20 is a related part but lacks the integrated boost controller, limiting it to buck-only topologies. Verify if the application requires the boost functionality provided by the L99LD21. No other direct substitute part numbers are confirmed in the provided documentation.