Linear LT3964双路同步降压LED驱动器解决方案

Linear公司的LT396是具有I2C接口的双路同步降压DC／DC转换器,工作在恒流和恒压源模式,非常适合于LED驱动器.工作电压4V－36V,恒流稳流±3%,1000:1外接真彩色PWM调光,10:1外接模拟调光,可调开关频率200kHz-2MHz,主要用在通用,工业,医疗和汽车照明,恒流和恒压源.本文介绍了LT3964主要特性,框图和多种应用电路,以及演示板DC2424A主要特性,电路图和材料清单.
The LTR3964 is a dual synchronous step-down DC／DCconverter with I2C interface designed to operate as aconstant-current and constant-voltage source and is idealfor driving LEDs. The fixed frequency and peak currentmode topology result in stable operation over a wide rangeof supply and output voltages. The ground referred voltage FB pin serves as the input for several LED protectionfeatures, and also allows the converter to operate as aconstant-voltage source. The maximum output current isset by an external resistor, and the output current amplifierhas a rail-to-rail common mode range. LT3964 usesan I2C interface to communicate with a microcontrollerto read LED faults, write PWM and analog dimming registersand set fault masking. The I2C PWM input providesLED dimming ratios up to 8192:1. The I2C programmableCTRL register sets the gain of the external CTRL pin, andmaximum current sense threshold, providing additional analog dimming capability.
LT3964主要特性:
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-L...