Analog Devices LT3964 | Demoboard LT Journal Aug 2018

Description

Released on LT JournalThe LTR3964 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, andmaximum current sense threshold, providing additional analog dimming capability.

Features

• 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 and10:1 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

Typical applications

• Constant-Current, Constant-Voltage Source
• General Purpose, Industrial, Medical and Automotive Lighting

More information

• Datasheet
• IC product information