Dual 36V Synchronous 1.6A Buck LED Driver with IC

The LT3964 is a dual synchronous step-down DC/DC converter with I2C interface designed to operate as a constant-current and constant-voltage source and is ideal for driving LEDs. The fixed frequency and peak current mode topology result in stable operation over a wide range of supply and output voltages. The ground referred voltage FB pin serves as the input for several LED protection features, and also allows the converter to operate as a constant-voltage source. The maximum output current is set by an external resistor, and the output current amplifier has a rail-to-rail common mode range. LT3964 uses an I2C interface to communicate with a microcontroller to read LED faults, write PWM and analog dimming registers and set fault masking. The I2C PWM input provides LED dimming ratios up to 8192:1. The I2C programmable CTRL register sets the gain of the external CTRL pin, and maximum current sense threshold, providing additional analog dimming capability.

Applications

* General Purpose, Industrial, Medical and Automotive Lighting

* Constant-Current, Constant-Voltage Source

* Wide Input Voltage Range: 4V to 36V

* Two Independent 1.6A/40V Synchronous Bucks

* I2C Interface for Internal True Color PWM™ Dimming (8192:1), Analog Dimming and Fault Reporting

* 1000:1 External True Color PWM Dimming and 10:1 External Analog Dimming

* PMOS Switch Driver for PWM and Output Disconnect

* ±3% Constant Current Regulation

* Adjustable Frequency: 200kHz to 2MHz

* Frequency Synchronization with Clock Output

* Programmable OPENLED Protection with Reporting

* Short-Circuit Protection with Reporting

* Programmable Undervoltage Lockout with Hysteresis

* Internal Compensation

* 9 Unique Device Addresses for I2C

* Available in 5mm × 6mm 36-Lead QFN Package