LT8355-1 Multi-Topology DC/DC Controller

ADI's LT8355-1 is a multi-topology DC-to-DC controller designed to drive two strings of high-current LEDs with independent dual channels that support LED strings up to 120 V. This product has an external PWM dimming ratio of 20,000:1 and an exponential internal control for a smooth change in brightness over the dimming range, creating an optimal human eye perception experience.

Evaluation board EVAL-LT8355-1-AZ is a high-voltage dual LED controller featuring the LT8355-1. Channel 1 is assembled as a boost LED driver and channel 2 as a buck-boost mode LED driver. Either channel can be altered to a boost LED driver or buck-boost mode LED driver by adjusting the FB network and LED connection. EVAL-LT8355-1-AZ drives a single string of LEDs per channel when the input is between 8 V and 18 V. Channel 1 drives up to 72 V of LEDs at 450 mA and channel 2 drives up to 30 V of LEDs at 1 A. EVAL-LT8355-1-AZ has an undervoltage lockout (UVLO) set at 6.2 V falling and 7.5 V rising. EVAL-LT8355-1-AZ features PWM dimming, analog dimming, shutdown, open LED, and short LED fault protection and reporting.

Features

• Independent dual channels support high-voltage LED strings up to 120 V
• 128:1 internal exponential PWM dimming delivers uniform and stable dimming without using external microcontrollers or software
• 20,000:1 external dimming ratio for extreme ambient light conditions