Eight-switch matrix LED dimmer simplifies complex designs

A new LED bypass switching device that enables independent dimming and diagnostics of eight individual LEDs or LED segments, the LT3965 has been introduced by Linear Technology. The device works in conjunction with an LED driver circuit configured as a current source. It features eight individually controlled floating 17V/330mO NMOS switches. Using these internal power switches and an integrated I2C serial interface, individual LEDs within the string can be turned on or off, or they can be PWM dimmed to offer unique patterns within the LED matrix. Typical applications include automotive matrix LED headlights, industrial lighting and large LED display lighting. The I2C serial interface enables digital programming with 256:1 dimming ratios with or without the 11-bit resolution fade transition between the dimming states. Each switch can control and monitor a single LED or a segment of up to 16V of series-connected LEDs. The LT3965’s 8V to 60V input voltage range can accommodate a wide range of LED drivers commonly used in automotive and industrial applications. For larger LED matrix applications, multiple LT3965s (up to 16) can use a common I2C bus, says the company.