DS3991 Datasheet, PDF (1/16 Pages) Maxim Integrated Products – Low-Cost CCFL Controller

Rev 0; 1/08
Low-Cost CCFL Controller
General Description
The DS3991 is a controller for cold-cathode fluorescent
lamps (CCFLs) that are used to backlight liquid-crystal
displays (LCDs). The DS3991 is available for both
push-pull and half-bridge drive topologies.
The DS3991 converts a DC voltage (5V to 24V) to the
high-voltage (300V_RMS to 1400V_RMS) AC waveform that
is required to power the CCFLs. The push-pull and half-
bridge drive schemes use a minimal number of external
components, which reduces component and assembly
cost and makes the printed circuit board (PCB) design
easy to implement. Both drive schemes provide an effi-
cient DC to AC conversion and produce near-sinu-
soidal waveforms.
LCD PC Monitors
LCD TVs
Applications
Features
♦ CCFL Controller for Backlighting LCD Panels
♦ Minimal External Components Required
♦ Lamp Fault Monitoring for Lamp-Open, Lamp-
Overcurrent, Failure-to-Strike, and Overvoltage
Conditions
♦ Accurate (±5%) On-Board Oscillator for Lamp
Frequency (40kHz to 80kHz)
♦ Accurate (±5%) On-Board Oscillator for DPWM
Burst-Dimming Frequency (80Hz to 300Hz)
♦ Device Supply Undervoltage Lockout
♦ Inverter Supply Undervoltage and Overvoltage
Lockouts
♦ Soft-Start on Burst-Dimming Minimizes Audible
Transformer Noise
♦ Strike Frequency Boost
♦ 100% to < 10% Dimming Range
♦ Low Cost
♦ Single-Supply Operation Range: 4.5V to 5.5V
♦ Temperature Range: -40°C to +85°C
♦ 16-Pin SO Package (150 mils)
PART
CONFIGURATION
DS3991V+C
Push-Pull
DS3991V+T&R/C
Push-Pull
DS3991V+
Half-Bridge
DS3991V+T&R
Half-Bridge
+Denotes a lead-free package.
T&R = Tape and reel.
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
Typical Operating Circuits appear at end of data sheet.
Ordering Information
DIMMING FREQUENCY RANGE (Hz)
80 to 300
80 to 300
80 to 300
80 to 300
PIN-PACKAGE
16 SO (150 mils)
16 SO (150 mils)
16 SO (150 mils)
16 SO (150 mils)
Pin Configuration
TOP VIEW
SLOPE 1
VCC 2
VCC 3
VCC 4
LOSC 5
POSC/PWM 6
BRIGHT 7
PWM_EN 8
DS3991
SO
16 SVML
15 SVMH
14 VCC
13 GND
12 OVD
11 LCM
10 GB
9 GA
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.