Two-Channel, Push-Pull CCFL Controller

The DS3992 is a low-cost, two-channel controller for cold-cathode fluorescent lamps (CCFLs) that are used to backlight liquid crystal displays (LCDs). The DS3992 can drive multiple CCFLs per channel, making it ideal for 4- and 6-lamp LCD PC monitor and TV applications.

The DS3992 uses a push-pull drive scheme to convert a DC voltage (5V to 24V) to the high voltage (300VRMS to 1400VRMS) AC waveform that is required to power the CCFLs. The push-pull drive scheme uses a minimal number of external components, which reduces component and assembly cost and makes the printed circuit board (PC board) design easy to implement. The push-pull drive scheme also provides an efficient DC-to-AC conversion and produces near-sinusoidal waveforms.

Applications

* LCD PC Monitors * LCD-TVs

* Two-Channel CCFL Controller for Backlighting LCD Panels for PC Monitors and LCD-TVs

* Minimal BOM Provides Low-Cost Inverter Solution

* Per-Channel Lamp Fault Monitoring for Lamp-Open, Lamp Overcurrent, Failure to Strike, and Overvoltage Conditions

* Accurate (±10%) On-Board Oscillator for Lamp Frequency (40kHz to 80kHz)

* Accurate (±10%) On-Board Oscillator for DPWM Burst-Dimming Frequency (90Hz to 220Hz or 180Hz to 440Hz)

* Device Supply Undervoltage Lockout

* Inverter Supply Undervoltage Lockout

* Burst-Dimming Soft-Start Minimizes Audible Transformer Noise

* Strike Frequency Boost

* 100% to < 10% Dimming Range

* 4.5V to 5.5V Single-Supply Operation

* -40°C to +85°C Temperature Range

* 16-Pin SO Package (150 mils)