LT8355-1 Series

60VIN/120VOUTDual LED Controller with Exponential PWM and Scalable Dimming

Catalog

60VIN/120VOUTDual LED Controller with Exponential PWM and Scalable Dimming

Part	Topology	Type	Voltage - Supply (Min) [Min]	Dimming	Mounting Type	Supplier Device Package	Number of Outputs	Package / Case	Grade	Frequency [Max]	Frequency [Min]	Internal Switch(s)	Operating Temperature [Min]	Operating Temperature [Max]
Analog Devices LT8355IUFDM-1#WTRPBF	SEPIC Step-Down (Buck) Step-Up (Boost)	DC DC Controller	5 V	Analog PWM	Surface Mount Wettable Flank	28-QFN (4x5)	2	28-WFQFN Exposed Pad	Automotive	2.1 MHz	96 kHz		-40 °C	125 ¯C
Analog Devices LT8355IUFDM-1#WPBF	SEPIC Step-Down (Buck) Step-Up (Boost)	DC DC Controller	5 V	Analog PWM	Surface Mount Wettable Flank	28-QFN (4x5)	2	28-WFQFN Exposed Pad	Automotive	2.1 MHz	96 kHz		-40 °C	125 ¯C

Catalog

60VIN/120VOUTDual LED Controller with Exponential PWM and Scalable Dimming

Key Features

• Two independent High Voltage LED Driver Controllers Channels

• 128:1 Internal Exponential PWM Dimming

• Two-Pin Multiplying Analog Dimming (CH2)

• Spread Spectrum Frequency Modulation

• 20,000:1 External PWM Dimming at 100Hz

• Rail-to-Rail LED Current Sensing: 0V to 120V

• ±2% LED Current Regulation

• ±2% Output Voltage Regulation

• LED Short/Open Protection and Indication

• Wide Input Voltage Range (5V to 60V)

• PMOS Switch Driver for PWM and Output Disconnect

• Independent Channel Dimming

• Constant-Voltage and Constant-Current Regulation

• Adjustable Switching Frequency 100kHz to 2MHz

• Independent OPEN/SHORT LED FAULT per channel

• Programmable VINUVLO with Hysteresis

• Side Solderable 28-Lead 4mm × 5mm QFN Package

• AEC-Q100 Qualified for Automotive Applications

Description

The LT8355-1 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%.APPLICATIONSHigh Voltage LED ApplicationsAutomotive Head Lamps/Running LampsAccurate Current Limited Voltage RegulatorAll registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 7199560, 7321203, 7746300, 8116045.