LT8355-1 Datasheet | Analog Devices

FEATURES n Two independent High Voltage LED Driver Controllers Channels n 128:1 Internal Exponential PWM Dimming n Two-Pin Multiplying Analog Dimming (CH2) n Spread Spectrum Frequency Modulation n 20,000:1 External PWM Dimming at 100Hz n Rail-to-Rail LED Current Sensing: 0V to 120V n ±2% LED Current Regulation n ±2% Output Voltage Regulation n LED Short/Open Protection and Indication n Wide Input Voltage Range (5V to 60V) n PMOS Switch Driver for PWM and Output Disconnect n Independent Channel Dimming n Constant-Voltage and Constant-Current Regulation n Adjustable Switching Frequency 100k Hz to 2MHz n Independent OPEN/SHORT LED FAULT per channel n Programmable VIN UVLO with Hysteresis n Side Solderable 28-Lead 4mm × 5mm QFN Package n AEC-Q100 Qualified for Automotive Applications APPLICATIONS n High Voltage LED Applications n Automotive Head Lamps/Running Lamps n Accurate Current Limited Voltage Regulator DESCRIPTION The LT®8355-1 a dual-channel DC/DC controller designed to drive two strings of high current LEDs. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. Voltage feedback pins serve as the inputs for several LED protection features and makes it possible for the converters to operate as a constant-voltage sources. The LT8355-1 senses output current at the high or low side of the load. The product of CTRL2 and IADJ2 inputs provides analog programming of the output current for channel 2. Channel 1 output current is programmed through CTRL1 input. The PWM input and PWMTG high side PMOS driver provides precision time-based LED dimming capability. When driven by an external digital signal, the PWM input provides LED dimming ratios of up to 20,000:1 at 100Hz. When driven by a constant voltage, the PWM input selects from one of 128 internally generated, precision, exponentially spaced dimming ratios ranging from 0.78% up to 100%. All registered trademarks and trademarks are the property of...