The LT1768 is a chip designed to control single or multiple cold cathode fluorescent lamps (CCFL) displays. It uses a unique multi-mode dimming scheme that combines both linear and PWM control functions to maximize lamp life, efficiency, and dimming range. The LT1768 can detect and protect against lamp failures and overvoltage start-up conditions. It is designed to provide maximum flexibility with a minimum number of external components. The LT1768 is a high power application's 1.5A MOSFET driver current mode PWM controller. It contains a 350kHz oscillator, 5V reference, and a current sense comparator with a 100mV threshold. It operates from an 8V to 24V input voltage. The LT1768 also has undervoltage lockout, thermal limit, and a shutdown pin that reduces supply current to 65µA. It is available in a small 16-lead SSOP package.
The LT1768 is a current‑mode PWM controller designed for single‑ or multiple‑lamp CCFL displays. It offers ultrawide multimode dimming, programmable PWM dimming, open‑lamp detection and protection, and operates from an 8 V to 24 V input voltage. The device includes a 5 V reference, a 350 kHz oscillator, and a 100 mV current‑sense threshold comparator.
The document provides absolute maximum ratings, detailed electrical characteristics, pin descriptions, typical performance curves, and a 16‑lead SSOP package layout. Typical application circuits for 4 W single‑lamp CCFL supplies are also included.
| Input Voltage Range | 8 V to 24 V |
|---|---|
| Package | 16‑Lead Plastic SSOP |
The LT1768 operates from 8 V to 24 V.
The PROG pin controls lamp current by converting a DC input voltage to source current into the VC pin.