Wide input voltage range from 4V to 36V, supports switching frequency up to 2MHz.

Analog Devices announced the release of the LT3964, a dual-channel 36V high-efficiency synchronous step-down LED driver that simplifies LED dimming control by incorporating a 40V, 1.6A power switch and an I2C interface.

The LT3964 is a highly integrated, compact solution featuring two independently controlled LED drivers with a wide input voltage range from 4V to 36V and support for a switching frequency of up to 2MHz, and requires fewer external components.

The LT3964 operates in fixed-frequency current mode control and functions as a constant-current, constant-voltage source capable of precise current control to provide optimal LED lighting in automotive, industrial, and architectural lighting applications. Synchronous operation exhibits an efficiency of over 94% on both channels under maximum current load.

The LT3964's 400kHz I2C interface significantly simplifies digital PWM dimming. There is no need for a PWM signal from the microcontroller to the LED driver; instead, internal registers must be programmed with the required dimming duty cycle synchronized with the internal clock. This interface provides a dimming ratio of up to 8192:1 and eliminates the beat frequency that occurs when the PWM signal and the internal oscillator are not synchronized. When using analog dimming, the analog dimming can be controlled more precisely by setting the ratio of the control voltage to the LED current using an 8-bit scale factor configurable via I2C. A 1000:1 external PWM dimming and a 10:1 analog dimming ratio are also provided.

The switching frequency of the LT3964 can be set within the range of 200kHz to 2MHz or synchronized with an external clock signal. LED driver protection features include detection of open circuit and short circuit faults, as well as LED overcurrent and overvoltage, all of which can be reported via the I2C interface. Additionally, a thermal shutdown function is supported as an extra protection feature.