Analog Devices LT3967

Description

The LT3967 is an LED bypass switching device for dimming individual LEDs in a string using a common current source. It features eight individually controlled floating source 15V/110mΩ NMOS switches. The eight switches can be connected in parallel and/or in series to bypass current around LEDs in a string. The LT3967 uses the I2C serial interface to communicate with a microcontroller. Each of the eight channels can be independently programmed to bypass the LED string in constant on or off, or PWM dimming with or without fade transition. Using the programmable fade option provides 11-bit resolution exponential transition between PWM dimming states. The LT3967 provides an internal clock generator and also supports an external clock source for PWM dimming. The LT3967 reports fault conditions for each channel such as open LED and shorted LED. The four address pins allow 16 LT3967 devices to share the I2C bus and define the power-up state of the switches.

Features

• Eight Independent 15V/110mΩ NMOS Switches
• Controls LED Dimming of Strings Up to 54V
• I2C Serial Interface with Programmable Address
• I2C Packet Error Checking with CRC-8
• Programmable 256:1 (8-Bit) PWM Dimming
• 11-Bit Precision Exponential Fade with Programmable Time
• Independent On/Off Control for Each Switch
• Programmable Shorted/Open LED Threshold with Fault Reporting
• Internal PWM Signal Generator
• Programmable Watchdog Timer
• Accurate VIN Referred Enable Pin
• User Defined Power-Up/Reset State of Switches
• Thermally Enhanced TSSOP Package

Typical applications

• Automotive LED Headlight Clusters
• Large LED Displays / RGBW Color Mixing Lighting

More information

• Datasheet
• IC product information