Dual LED controller with scalable dimming

Analog Devices Inc LT8355-1 Dual LED Controller, available now from Mouser, is a dual-channel constant-frequency, CC/CV boost power stage controller created to drive two strings of high-current LEDs. The device's fixed frequency, current mode architecture produces stable operation across various supply and output voltages. Voltage feedback pins act as the inputs for multiple LED protection features and make it feasible for the converters to function as constant-voltage sources.

The device senses output current at the high-side or low-side of the load. The product of CTRL2 and IADJ2 inputs supply analog programming of the output current for channel 2. Channel 1 output current is programmed via CTRL1 input. The PWM input and PWMTG high-side PMOS driver provide precision time-based LED dimming ability. When driven by an external digital signal, the PWM input supplies LED dimming ratios of up to 20,000:1 at 100Hz. When driven by a constant voltage, the PWM input chooses from one of 128 internally generated, precision, exponentially spaced dimming ratios ranging from 0.78% to 100%.

The LED controller is provided in a side solderable 4mm x 5mm QFN-28 package and is AEC-Q100 qualified for automotive applications, typically for high-voltage LED applications, headlamps and running lamps, and accurate current-limited voltage regulators.