Rainbow Electronics MAX754 - Manual

_______________General Description
The MAX753/MAX754 drive cold-cathode fluorescent
lamps (CCFLs) and provide the LCD backplane bias
(contrast) power for color or monochrome LCD panels.
These ICs are designed specifically for backlit note-
book-computer applications.
Both the backplane bias and the CCFL supply can be
shut down independently. When both sections are shut
down, supply current drops to 25µA. The LCD contrast
and CCFL brightness can be adjusted by clocking sep-
arate digital inputs or using external potentiometers.
LCD contrast and backlight brightness settings are pre-
served in their respective counters while in shutdown.
On power-up, the LCD contrast counter and CCFL
brightness counter are set to one-half scale.
The ICs are powered from a regulated 5V supply. The
magnetics are connected directly to the battery, for
maximum power efficiency.
The CCFL driver uses a Royer-type resonant architec-
ture. It can provide from 100mW to 6W of power to one
or two tubes. The MAX753 provides a negative LCD
bias voltage; the MAX754 provides a positive LCD bias
voltage.
________________________Applications
Notebook Computers
Palmtop Computers
Pen-Based Data Systems
Personal Digital Assistants
Portable Data-Collection Terminals
____________________________Features
♦ Drives Backplane and Backlight
♦ 4V to 30V Battery Voltage Range
♦ Low 500µA Supply Current
♦ Digital or Potentiometer Control of CCFL
Brightness and LCD Bias Voltage
♦ Negative LCD Contrast (MAX753)
♦ Positive LCD Contrast (MAX754)
♦ Independent Shutdown of Backlight and
Backplane Sections
♦ 25µA Shutdown Supply Current
______________Ordering Information
* Contact factory for dice specifications.
MAX753/MAX754
CCFL Backlight and
LCD Contrast Controllers
________________________________________________________________ Maxim Integrated Products 1
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
LFB
BATT
LX
LDRV CON
LON
LADJ
V DD
MAX753
MAX754
PGND
CDRV
CS
CC CFB
REF
GND
CADJ
DIP/SO
TOP VIEW
__________________Pin Configuration
Call toll free 1-800-998-8800 for free samples or literature.
19-0197; Rev 1; 1/95
PART TEMP. RANGE
MAX753 CPE 0°C to +70°C
MAX753CSE 0°C to +70°C
MAX753C/D 0°C to +70°C Dice*
16 Narrow SO
16 Plastic DIP
PIN-PACKAGE
MAX753EPE -40°C to +85°C
MAX753ESE -40°C to +85°C 16 Narrow SO
16 Plastic DIP
MAX754 CPE 0°C to +70°C
MAX754CSE 0°C to +70°C
MAX754C/D 0°C to +70°C Dice*
16 Narrow SO
16 Plastic DIP
MAX754EPE -40°C to +85°C
MAX754ESE -40°C to +85°C 16 Narrow SO
16 Plastic DIP
Block Diagram located at end of data sheet.