DS3994：4-Channel Cold-Cathode Fluorescent Lamp Controller

Allows the Implementation of Scanning Backlight Schemes Using Only One CCFL Controller IC

The DS3994 is a 4-channel controller for cold-cathode fluorescent lamps (CCFLs) that backlight liquid crystal displays (LCDs) in TV and PC monitor applications. The DS3994's features make it suitable for use in even the largest LCDs, while its low BOM cost makes it ideal for the entire range of LCD TVs and monitors. The DS3994 can stagger the lamp bursts from each of the four channels. This feature allows scanning backlight schemes for video quality improvement to be implemented using a single CCFL controller IC, making it very simple and inexpensive to provide this enhancement. In addition, staggering the bursts from each channel can be used to minimize current ripple on the display power supply, which is especially important for larger LCDs. The relative stagger between each of the channels is programmable, so this feature can be tailored to the specific application. The DS3994 uses a push-pull drive architecture but it can also support full and half bridge drive schemes. Contact the factory for more details.

Key Features

High-Density CCFL Controller for LCD TV and PC Monitor Backlights
Programmable Staggered Start for Burst Dimming on Each Channel
Strike Frequency Boost Option
Programmable Strike Time
Can Be Easily Cascaded
Minimal External Components
Analog Brightness Control
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 (±2%) On-Board Oscillator Lamp Frequency (20kHz to 80kHz)
Wide Range On-Board DPWM Burst-Dimming Oscillator (22.5Hz to 440Hz)
Can Be Synchronized to External Sources for the Lamp and DPWM Frequencies
< 10% to 100% Dimming Range
Soft-Start Minimizes Audible Transformer Noise
I²C-Compatible Serial Port and On-Board Nonvolatile (NV) Memory Allow Device Customization
3-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
28-Pin SO (300 mils) Package

DS3994: Typical Operating Circuit

Applications/Uses

LCD PC Monitors
LCD-TVs

DataSheet

title	Download file
DS3994 Data Sheet	DS3994.pdf

Parametrics

Part Number	V_IN (V)	V_IN (V)	Topology	Channels	Dimming Interface	Freq.	Package/Pins	Oper. Temp. (°C)	Budgetary Price
Part Number	min	max	Topology	Channels	Dimming Interface	Freq.	Package/Pins	Oper. Temp. (°C)	See Notes
DS3994	4.5	5.5	Push-Pull	4	Analog DPWM I2C SMBus	Fixed PWM	SOIC(W)/28	-40 to +85	$1.68 @1k

Quality and Environmental Data

DS3994.pdf

Ordering Information

Part Number	Status	Package	Temp	RoHS
DS3994Z+	Active	SOIC(W),;28 pin;192.8 mm²	-40°C to +85°C	Lead Free
DS3994Z+T&R	Active	SOIC(W),;28 pin;192.8 mm²	-40°C to +85°C	Lead Free
DS3994Z+W	Active	SOIC(W),;28 pin;192.8 mm²	-40°C to +85°C	Lead Free