LX27912IDW

The LX27912 is a high performance LED controller optimized for LCD-TV and other LCD display systems and provides a cost competitive solution for off-PFC LED drive applications. The controller provides a versatile solution for both DC power regulation and LED drive control within a single 24 pin IC chip. In addition, the power circuit architecture supported by LX27912 allows the designer to use a single power transformer and single primary switching stage with Microsemi’s proprietary synchronous regulation technology to supply both the DC outputs and LED drive power, further saving the total cost of the power system. The device provides on chip 5.25V output from VIN input with the working range of up to 27V. The controller provides two sets of drive signals: AOUT and BOUT to drive a LLC switching stage, and COUT to drive a synchronous regulation stage, both with independent control loop. The drive format of COUT can be further configured by the voltage level of ENABLE signal to support either synchronous regulation operation or direct LED current control to satisfy a particular PWM dimming requirement. In addition, a proprietary ACU_BRITE algorithm is incorporated in the dimming control operation to allow the user to adaptively adjust the PWM dimming duty to achieve accurate brightness control over a wide dimming duty cycle range while maintaining the highest operating efficiency. It also provides analog LED current control to allow the system to change the LED current dynamically in real time to facilitate particular application requirement such as display mode switching between 2D and 3D. Direct PWM input dimming operation can be realized by inputting a dimming pulse train to DIM pin directly. The synchronous regulation technology and ACU_BRITE algorithm changes the traditional approach in LED backlight control. The synchronous regulation scheme helps user to eliminate the DC-DC converter stage and ACU_BRITE algorithm maintains accurate brightness control without the need of a dimming control switch to turn on and off the LED current directly, providing the benefits of both cost saving and efficiency improvement without compromise of performance. A versatile set of system monitoring and protection functions are also incorporated in the LX27912 design to provide reliable protection of the device and the system. In addition the LX27912 supports standby power control thus providing a single system controller. The device is available in 24 lead SOIC surface mount package in the industrial temperature range.