General Description

The DS3984 is a 4-channel controller for cold-cathode

fluorescent lamps (CCFLs) used to backlight liquid

crystal displays (LCDs) in TV and PC monitor applica-

tions. The DS3984 supports configurations of 1 to 4

lamps, and multiple DS3984 controllers can be cascad-

ed to support applications requiring more than 4 lamps.

Applications

LCD Televisions

LCD PC Monitors

Features

♦ High-Density CCFL Controller for LCD TV and PC

Monitor Backlights

♦ Can Be Easily Cascaded to Support More Than

4 Lamps

♦ Minimal External Components

♦ Analog Brightness Control

♦ Per-Channel Lamp Control Ensures Equal

Brightness Among Lamps and Maximizes Lamp

Life

♦ Gate Driver Phasing Minimizes DC Supply Current

Surges

♦ Per-Channel Lamp Fault Monitoring for Lamp

Open, Lamp Overcurrent, Failure to Strike, and

Overvoltage Conditions

♦ Accurate (±5%) Independent On-Board Oscillators

for Lamp Frequency (40kHz to 80kHz) and DPWM

Burst Dimming Frequency (22.5Hz to 440Hz)

♦ Can Be Synchronized to External Sources for the

Lamp and DPWM Frequencies

♦ <10% to 100% Dimming Range

♦ Programmable Soft-Start Minimizes Audible

Transformer Noise

Nonvolatile (NV) Memory Allow Device

Customization

♦ 8-Byte NV User Memory for Storage of Serial

Numbers and Date Codes

♦ 4.5V to 5.5V Single-Supply Operation

♦ -40°C to +85°C Temperature Range

♦ 32-Lead TQFP (7mm x 7mm) Package or

28-Pin SO (300 mils) Package

4-Channel Cold-Cathode

Fluorescent Lamp Controller

______________________________________________ Maxim Integrated Products

1

28

27

26

25

24

23

22

21

20

19

18

17

16

15

1

2

3

4

5

6

7

8

9

10

11

12

13

14

LSYNC

FAULT

SCL

SDA

OVD4

LCM4

GND

GB4

GA4

OVD3

LCM3

GB3

GA3

OVD2

LCM2

GB2

GA2

OVD1

LCM1

GB1

GA1

SVM

BRIGHT

POSC

PSYNC

A0

LOSC

28-SO-300

TOP VIEW

DS3984

Pin Configurations

Rev 0; 4/05

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

Typical Operating Circuit appears at end of data sheet.

Pin Configurations continued at end of data sheet.

PART

TEMP RANGE

PIN-PACKAGE

DS3984T

-40°C to +85°C

32 TQFP

DS3984T+

-40°C to +85°C

32 TQFP

DS3984Z

-40°C to +85°C

28 SO.300

DS3984Z+

-40°C to +85°C

28 SO.300

nents from Maxim Integrated Products, Inc., or one of its subli-

censed Associated Companies, conveys a license under the

Specification as defined by Philips.

+Denotes lead-free package.