LM3431EVAL

Evaluation Board for the 3Channel Constant Current LED Driver with Integrated Boost Controller

The is an evaluation board for LM3431, a combination switching boost voltage regulator and multi channel current controller. The evaluation board is designed to drive four parallel strings of eight series LEDs at 140mA per string from an input voltage range of 8V to 18V. The boost switcher regulates LED cathode voltage for optimum efficiency, while allowing the output voltage to vary according to the LED forward voltage. The LM3431 incorporates complete fault protection features including LED short and open protection, over current protection, over voltage and under voltage protection and thermal shutdown. The error detection flag can be monitored at the DLY post, which has a programmable delay time. The board includes a DIM input terminal for a selectable digital or analog dimming control signal. PWM dimming frequencies up to 1kHz at 100:1 contrast ratio and contrast ratios up to 500:1 at 200Hz are possible.

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Three channel programmable LED current

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High accuracy linear current regulation

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Analog and digital PWM dimming control

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Up to 25kHz dimming frequency

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Integrated boost controller

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5V to 36V input voltage range

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Adjustable switching frequency up to 1MHz

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LED short and open protection

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Selectable fault shutdown or automatic restart

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Programmable fault delay