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
Applications/Uses
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
Notes: **This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
duties, taxes, fees, and exchange rates. For volume-specific prices
and delivery, please see the price and availability page
or contact an authorized distributor.