OZ965IG

Features:

• Single-stage power conversion, requiring only a +5 V voltage source
• Reduces the number of components and board size by 30% compared with conventional 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


Specifications

VDD	5.5V
GND	+/- 0.3V
Logic inputs	-0.3 V to VDD+0.3V
	OZ965	OZ965I
Operating temp.	0 to 70	-40 to 85
Operating junction temp.	150
Storage temp.	-55 to 150
	OZ965	OZ965I
Power dissipation - 16-pin SOP - 16-pin TSSOP	.720W .690W	.580W .550W
Thermal Impedance - 16-pin SOP - 16-pin TSSOP	111/W 115/W	111/W   115/W

Description

The OZ965IG 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 OZ965IG 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 OZ965IG utilizes the low energy loss resonate mode principle to deliver a very high efficiency inverter. The OZ965IG 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 of OZ965IG are approximately sinusoidal. This sinusoid results in very little harmonic emi/rfi emissions.

The OZ965IG 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 OZ965IG 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 OZ965IG is available in 16-pin SOP and TSSOP packages. It is specified over the commercial temperature range of 0 to +70, and the industrial temperature range of -40 to +85.