●GENERAL DESCRIPTION
●The OZ965 is a single chip, high-efficiency, Cold Cathode Fluorescent Lamp (CCFL) backlight
●inverter controller whose primary function is to convert +5 volt DC power to approximately 600
●VAC. Additionally, the OZ965 performs the lamp dimming function with an analog voltage or low
●frequency Pulse Width Modulation (PWM) control.
●Operating Principle:
●The CCFL tube, transformer secondary, and capacitor form a resonant circuit. The OZ965 utilizes the low energy loss resonate mode principle to deliver a very high efficiency inverter. The OZ965 drives the transformer primary with a variable pulse width voltage directly from the +5v supply. The resultant primary drive current is alternately reversing with zero-voltage-switching.
●Because of the transformer leakage inductance and the secondary resonant circuit, the secondary voltage and current are approximately sinusoidal. This sinusoid results in very little harmonic emi/rfi emissions.
●The OZ965 operates at a single, constant frequency in a PWM mode. Typical operating frequency ranges between 30 KHz to 200 KHz, dependent upon the CCFL and transformer characteristics. Intelligent open-lamp protection provides design flexibility so various transformer models/manufacturers may be used. Its high driving capability allows the OZ965 to drive high power MOSFETs.The single stage design results in a low cost, reliable transformer without expensive, less reliable secondary fold-back treatment. The transformer does not require a more expensive center tapped primary.
●The OZ965 is available in 16-pin SOP and TSSOP packages. It is specified over the commercial temperature range of 0°C to +70°C, and the industrial temperature range of -40°C to +85°C.
●FEATURES
●• Single-stage power conversion, requiring only a +5 V voltage source
●• Reduces the number of components and board size by 30% compared with onventional design
●• Supports both floating and grounded secondary designs
●• 90% efficiency vs. typical 75% efficiency of conventional designs
●• Internal open-lamp and short-circuit protections
●• Wide dimming range
●• Supports multiple CCFLs
●• Simple and reliable 2-winding transformer design
●• Eliminates leakage current when used in a floating secondary design
●• Constant-frequency design eliminates interference with LCDs
