CCFL Regulator backlights handheld computer displays.
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Press Release Summary:
Model LTC1697, rated at 1 W and housed in compact MSOP-10 package, drives one cold cathode fluorescent lamp (CCFL). It operates from 2.8-5.5 V input voltage, has 300 kHz fixed frequency operation, and incorporates internal PWM dimming system. Its 0.8 V reference and internal current sense maintain accurate lamp current. Synchronous current mode PWM control, with internal 1 A MOSFET switches, delivers efficiencies to 75%. Internal shutdown function reduces supply current to less than 2 µA.
Original Press Release:
High Efficiency, 1W CCFL Regulator Offers a Low Cost Alternative for Backlighting Handheld Computer Displays
MILPITAS, CA - March 17, 2004 - Linear Technology announces the LTC1697, a high efficiency, 1-watt CCFL regulator with internal MOSFETs in an MSOP-10 package. It is designed to drive a single cold cathode fluorescent lamp (CCFL) fused in small handheld displays. Operating from an input voltage range of 2.8V to 5.5V, the LTC1697 is ideal for single cell Li-Ion, and multicell NiMH/alkaline applications. An internal PWM dimming system maximizes both efficiency and dimming range while accurate lamp currents can be set with a single external resistor. Internal MOSFETs and a 300kHz fixed frequency operation ensure a small solution size and minimal switching noise.
The LTC1697 utilizes an internal synchronous current mode PWM control with internal 1A MOSFET switches to deliver efficiencies up to 75%. Its 0.8V reference and internal current sense maintain very accurate lamp current, maximizing lamp lifetime. Its internal shutdown function reduces supply current to less than 2uA. For handheld single CCFL applications, the LTC1697 offers the most compact, efficient available.
The LTC1697 is available from stock in an MSOP-10 package. Pricing starts at $1.95 each for 1,000-piece quantities.
Summary of Features: LTC1697
Drives a Single CCFL Lamp
Input Voltage Range of 2.8V to 5.5V
Synchronous Architecture for up to 75% Efficiency
Very Low Shutdown Current: <2uA
PWM Dimming Frequency Adjustable with Single Capacitor
Accurate Lamp Current Maximizes Lamp Lifetime
Fixed Frequency Operation at 300kHz
Internal or External PWM Dimming
Tiny MSOP-10 Package
Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators,power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequencydevices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.
Call toll-free 1-800-4-LINEAR (for literature only), or go to the company's web site: www.linear.com
Note: LT, AND LTC are registered trademarks of Linear Technology Corp.
