UCC2974

UCC3974

SLUS485A – JULY 2001 – REVISED NOVEMBER 2001

DUAL COLD CATHODE FLUORESCENT

LAMP CONTROLLER

1

www.ti.com

FEATURES

Supply Current

Capability

Resonant Tanks

APPLICATIONS

DESCRIPTION

Design goals for a cold cathode fluorescent lamp

(CCFL) converter used for a liquid crystal display

(LCD) monitor application include small size, high

efficiency, and low cost. The UCC2974/UCC3974

CCFL controllers provide the necessary circuit

blocks to implement a highly efficient LCD monitor

backlight supply in a small 16-pin TSSOP

package. The device features two control stages

for operating independent resonant tanks for

multi-lamp designs. The BiCMOS controller

typically consumes less than 2-mA of operating

current, improving overall system efficiency.

External parts count is minimized and system cost

is reduced by integrating such features as dual

PWM driver stages, open lamp protection,

overvoltage clamp, and synchronization circuitry

between the buck and push-pull stages. The

device operates in both analog and low-frequency

dimming modes.

Copyright

 2001, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

1

OUT1

16

OUT2

2VIN

15

GND

3

BUCK1

14

BUCK2

4

COMP1

13

CBP

5

FB1

12

COMP2

6RC

11

FB2

7RD

10

MODE

8DIM

9

LFDSYNC

UCC3974

VIN

VIN

VIN

BRIGHT

SYNC

TYPICAL APPLICATION

UDG–01023