DESCRIPTION

Microsemi’s LX1692 is a cost reduced, third generation Direct Drive CCFL (Cold Cathode Fluorescent Lamp) controller. The integrated controller is optimized to drive CCFL’s using resonant full bridge inverter topology.

Resonant full bridge topology provides near sinusoidal waveforms over a wide supply voltage range in order to maximize the life of CCFL lamps, control EMI emissions, and maximize efficiency. This new archi tecture also provides a wide dimming range.

The LX1692 includes safety features that limit the transformer secondary voltage and protect against fault conditions which include open lamp, broken lamp and short-circuit faults.

The LX1692 regulates the CCFL brightness in three ways: analog dimming, digital dimming, or combined analog and digital dimming methods simultaneously to achieve the widest dimming range (> 60 to 1).

The LX1692 can accept a brightness control signal that is either an analog voltage or a direct low frequency PWM. The LX1692 also features integrated gate drivers for the four external power MOSFETs.

An integrated 4V LDO powers all internal control circuitry which greatly simplifies supply voltage requirements. The LX1692 is available in a 20-Pin TSSOP and SOIC.

KEY FEATURES

■ For Wide Voltage Range Inverter Application (7V to 22V)

■ Patent Resonant Strike for Unsurpassed Striking Power Combined with Best Efficiency

■ Low Stress to Transformers

■ Excellent Open Circuit Voltage

Regulation Reduces Transformer

Breakdown Voltage

Requirements While Striking

Higher Voltage Lamps

■ One Inverter for Multiple Panel Types

■ Wide Dimming Range

Analog Dimming: >3 to 1

Digital Dimming : >20 to 1

Combined: >60 to 1

● Fool-Proof Striking

● Programmable Burst Dimming Frequency

● Programmable Time Out Protection

● Fixed Operating Frequency

● Open Lamp Voltage Protection, Short Lamp Protection, Arc Protection1

BENEFITS

■ Even Display Light Distribution

■ Longer Lamp Life with Optimized Lamp Current Amplitude

■ Reduced Operating Voltage Lowers Corona Discharge and Prolongs Module Life

■ High “Nits / Watt” Efficiency Makes Less Heat and Brighter Displays

APPLICATIONS

■ LCD TV

■ LCD Monitor