UCC2974 Datasheet, PDF (1/14 Pages) Texas Instruments – DUAL COLD CATHODE FLUORESCENT LAMP CONTROLLER

UCC2974
UCC3974
ą
SLUS485A – JULY 2001 – REVISED NOVEMBER 2001
DUAL COLD CATHODE FLUORESCENT
LAMP CONTROLLER
FEATURES
D Synchronous or Nonsynchronous Operation
D Dual Output and Control Stages
D BiCMOS Technology
D Accurate Current Control with 2-mA Typical
Supply Current
D Analog or Digital Low-Frequency Dimming
Capability
D Open Lamp Protection with Voltage Clamp
D 4.5-V to 25-V Operation
D PWM Frequencies Synchronized to External
Resonant Tanks
D TSSOP-16 (PW) Package
TYPICAL APPLICATION
VIN
VIN
BRIGHT
SYNC
VIN
UCC3974
1 OUT1
OUT2 16
2 VIN
GND 15
3 BUCK1 BUCK2 14
4 COMP1
CBP 13
5 FB1
COMP2 12
6 RC
FB2 11
7 RD
MODE 10
8 DIM LFDSYNC 9
UDG–01023
APPLICATIONS
D Portable PCs
D Desktop LCD Monitors
D Internet Appliances
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.
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.
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Copyright  2001, Texas Instruments Incorporated
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