Features and Benefits
- Fast Response to Input Change
- Wide Input Voltage Range (4.6V to 28V)
- High Power-to-Light Efficiency
- Minimizes Transformer Voltage Stress
- Lamp-Out Protection with 2s Timeout
- Buck Switch Short and Other Single-Point Fault Protection
- Integrated Royer MOSFET Drivers Reduce Transformer Pin Count
- Buck Operation Synchronized to Royer Oscillator
- Synchronizable DPWM Frequency
- Pin-Selectable Brightness Control Interface
- SMBus Serial Interface (MAX1739)
- Analog Interface (MAX1739/MAX1839)
The MAX1739/MAX1839 fully integrated controllers are optimized to drive cold-cathode fluorescent lamps (CCFLs) using the industry-proven Royer oscillator inverter architecture. The Royer architecture provides near sinusoidal drive waveforms over the entire input range to maximize the life of CCFLs. The MAX1739/MAX1839 optimize this architecture to work over a wide input voltage range, achieve high efficiency, and maximize the dimming range.
The MAX1739/MAX1839 monitor and limit the transformer center-tap voltage when required. This ensures minimal voltage stress on the transformer, which increases the operating life of the transformer and eases its design requirements. These controllers also provide protection against many other fault conditions, including lamp-out and buck short faults.
These controllers achieve 50:1 dimming range by simultaneously adjusting lamp current and "chopping" the CCFL on and off using a digitally adjusted pulse-width modulated (DPWM) method. CCFL brightness is controlled by an analog voltage or is set with an SMBus™-compatible two-wire interface (MAX1739).
The MAX1739/MAX1839 drive an external high-side N-channel power MOSFET and two low-side N-channel power MOSFETs, all synchronized to the Royer oscillator. An internal 5.3V linear regulator powers the MOSFET drivers and most of the internal circuitry. The MAX1739/MAX1839 are available in space-saving 20-pin QSOP packages and operate over the -40°C to +85°C temperature range.
- LCD Displays
- Palmtop Computers
Product Lifecycle Not Recommended for New Designs
This designates products ADI does not recommend broadly for new designs.
Documentation & Resources
MAX1739 Companion Parts
Recommended Related Parts
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
See our Ordering FAQs for answers to questions about online orders, payment options and more.
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.