DESCRIPTION

· The UCC3972/3 CCFL controllers are designed for Cold Cathode Fluorescent Lamp (CCFL) converters in notebook computers or portable applications, focusing on small size, high efficiency, and low cost.
· These controllers integrate essential circuit blocks for an efficient CCFL backlight power supply in an 8-pin TSSOP package.
· They feature a BiCMOS design with less than 1mA operating current, enhancing system efficiency compared to bipolar controllers.
· The controllers include a feedback controlled PWM driver stage, open lamp protection, startup delay, and synchronization circuitry, reducing external parts and system cost.
· They operate with input voltages from 4.5V to 25V and support analog and low frequency dimming modes.
· The UCC3973 includes a programmable voltage clamp at the BUCK pin to protect the transformer from overvoltage during startup or open lamp conditions.

FEATURES

· 1mA typical supply current.
· Accurate lamp current control.
· Analog or low frequency dimming capability.
· Open lamp protection.
· Programmable startup delay.
· 4.5V to 25V operation.
· PWM frequency synchronized to external resonant tank.
· Available in 8-pin TSSOP and SOIC packages.
· Internal voltage clamp protects transformer from over-voltage (UCC3973).

APPLICATIONS

· Notebook computers.
· Portable applications requiring CCFL backlight power supplies.