LED dimmer simplifies complex LED matrix designs

The LT3965 LED bypass switching device enables independent dimming and diagnostics of eight individual LEDs or LED segments. It works in conjunction with an LED driver circuit configured as a current source. It features eight individually controlled floating 17-V/ 330-mΩ NMOS switches. Using these internal power switches and an integrated I² C 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 for the LED Dimmer IC include automotive matrix LED headlights, industrial lighting and large LED display lighting. The I² C 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 16 V of series-connected LEDs. The device offers an 8 to 60-V input voltage range to accommodate a wide range of LED drivers commonly used in automotive and industrial applications. The IC’s eight switches can be connected in parallel and/or in series to bypass current around one or more LEDs in a string. It is offered in a 28-lead TSSOP thermally enhanced package. It is tested and guaranteed to operate from a –40° to 125°C operating junction temperature range. See the LT3965 video at www.linear.com/solutions/5973