Features

• Eight Independent 17V 330mΩ NMOS Switches
• Independent On/Off/Dimming Control of 1 to 4 LEDs for Each Switch
• I²C Multidrop Serial Interface with Programmable Open LED and Shorted LED Fault Reporting
• 16 Unique I²C Addresses
• V_DD Range: 2.7V to 5.5V and V_IN Range: 8V to 60V
• Digital Programmable 256:1 PWM Dimming
• Fade Transition Between PWM Dimming States
• Optional Internal Clock Generator or External Clock Source for PWM Dimming
• Open LED Overvoltage Protection
• Flicker Free PWM Dimming

Typical Application

Description

The LT®3965 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 17V/330mΩ NMOS switches. The eight switches can be connected in parallel and/or in series to bypass current around one or more LEDs in a string. The LT3965 uses the I²C serial interface to communicate with the 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 fade option provides 11-bit resolution logarithmic transition between PWM dimming states. The LT3965 provides an internal clock generator and also supports external clock source for PWM dimming. The LT3965 reports fault conditions for each channel such as open LED and shorted LED. The four address select pins allow 16 LT3965 devices to share the I²C bus. The device is available in a 28-lead TSSOP package.