Datasheet LT3964 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Dual 36V Synchronous 1.6A Buck LED Driver with I2C |
| Pages / Page | 36 / 1 — FEATURES. DESCRIPTION. Wide Input Voltage Range: 4V to 36V. Two … |
| File Format / Size | PDF / 3.8 Mb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide Input Voltage Range: 4V to 36V. Two Independent 1.6A/40V Synchronous Bucks
Model Line for this Datasheet
Text Version of Document
LT3964 Dual 36V Synchronous 1.6A Buck LED Driver with I2C
FEATURES DESCRIPTION
n
Wide Input Voltage Range: 4V to 36V
The LT®3964 is a dual synchronous step-down DC/DC n
Two Independent 1.6A/40V Synchronous Bucks
converter with I2C interface designed to operate as a n
I2C Interface for Internal True Color PWM™ Dimming
constant-current and constant-voltage source and is ideal
(8192:1), Analog Dimming and Fault Reporting
for driving LEDs. The fixed frequency and peak current n
1000:1 External True Color PWM Dimming and
mode topology result in stable operation over a wide range
10:1 External Analog Dimming
of supply and output voltages. The ground referred volt- n
PMOS Switch Driver for PWM and Output Disconnect
age FB pin serves as the input for several LED protection n ±3% Constant Current Regulation features, and also allows the converter to operate as a n Adjustable Frequency: 200kHz to 2MHz constant-voltage source. The maximum output current is n Frequency Synchronization with Clock Output set by an external resistor, and the output current ampli- n Programmable OPENLED Protection with Reporting fier has a rail-to-rail common mode range. LT3964 uses n Short-Circuit Protection with Reporting an I2C interface to communicate with a microcontroller n Programmable Undervoltage Lockout with Hysteresis to read LED faults, write PWM and analog dimming reg- n Internal Compensation isters and set fault masking. The I2C PWM input provides n 9 Unique Device Addresses for I2C LED dimming ratios up to 8192:1. The I2C programmable n Available in 5mm × 6mm 36-Lead QFN Package CTRL register sets the gain of the external CTRL pin, and maximum current sense threshold, providing additional
APPLICATIONS
analog dimming capability. n General Purpose, Industrial, Medical and All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203, 7746300. Automotive Lighting n Constant-Current, Constant-Voltage Source
TYPICAL APPLICATION 50W Dual Buck 1A LED Driver Efficiency, VIN = 34V IN
100 31V TO 36V VIN1 BST1 BOTH CHANNELS ARE ON (ENABLED AT 33V, 10µF 2.2µF 0.22µF 10µH 100mΩ SHUTDOWN ×2 100k GND SW1 95 AT 31V) 2.2µF EN/UVLO 1M 1A, 3.92k PWM1 PWM1 FB1 8 LEDs 90 PWM2 PWM2 UP TO CTRL1 43.2k CTRL2 26V INTVCC INTV 85 CC ISP1 2.2µF 100k ISN1 ALERT PWMTG1 EFFICIENCY (%) 80 LT3964 VIN2 BST2 0.22µF INTV 2.2µF CC 75 10µH 100mΩ 499k GND SW2 1M 2.2µF T 70 SET 1A, 100 200 300 400 500 600 700 800 900 1000 RT FB2 165k 27.4k 8 LEDs I 43.2k UP TO LED (mA) 2MHz 3964 TA01b SYNC/CLKOUT 26V ISP2 2-WIRE SCL ISN2 I2C INTERFACE SDA PWMTG2 ADDR1 ADDR2 3964 TA01a INTVCC 3964fb For more information www.linear.com/LT3964 1
FEATURES DESCRIPTION
n
Wide Input Voltage Range: 4V to 36V
The LT®3964 is a dual synchronous step-down DC/DC n
Two Independent 1.6A/40V Synchronous Bucks
converter with I2C interface designed to operate as a n
I2C Interface for Internal True Color PWM™ Dimming
constant-current and constant-voltage source and is ideal
(8192:1), Analog Dimming and Fault Reporting
for driving LEDs. The fixed frequency and peak current n
1000:1 External True Color PWM Dimming and
mode topology result in stable operation over a wide range
10:1 External Analog Dimming
of supply and output voltages. The ground referred volt- n
PMOS Switch Driver for PWM and Output Disconnect
age FB pin serves as the input for several LED protection n ±3% Constant Current Regulation features, and also allows the converter to operate as a n Adjustable Frequency: 200kHz to 2MHz constant-voltage source. The maximum output current is n Frequency Synchronization with Clock Output set by an external resistor, and the output current ampli- n Programmable OPENLED Protection with Reporting fier has a rail-to-rail common mode range. LT3964 uses n Short-Circuit Protection with Reporting an I2C interface to communicate with a microcontroller n Programmable Undervoltage Lockout with Hysteresis to read LED faults, write PWM and analog dimming reg- n Internal Compensation isters and set fault masking. The I2C PWM input provides n 9 Unique Device Addresses for I2C LED dimming ratios up to 8192:1. The I2C programmable n Available in 5mm × 6mm 36-Lead QFN Package CTRL register sets the gain of the external CTRL pin, and maximum current sense threshold, providing additional
APPLICATIONS
analog dimming capability. n General Purpose, Industrial, Medical and All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203, 7746300. Automotive Lighting n Constant-Current, Constant-Voltage Source
TYPICAL APPLICATION 50W Dual Buck 1A LED Driver Efficiency, VIN = 34V IN
100 31V TO 36V VIN1 BST1 BOTH CHANNELS ARE ON (ENABLED AT 33V, 10µF 2.2µF 0.22µF 10µH 100mΩ SHUTDOWN ×2 100k GND SW1 95 AT 31V) 2.2µF EN/UVLO 1M 1A, 3.92k PWM1 PWM1 FB1 8 LEDs 90 PWM2 PWM2 UP TO CTRL1 43.2k CTRL2 26V INTVCC INTV 85 CC ISP1 2.2µF 100k ISN1 ALERT PWMTG1 EFFICIENCY (%) 80 LT3964 VIN2 BST2 0.22µF INTV 2.2µF CC 75 10µH 100mΩ 499k GND SW2 1M 2.2µF T 70 SET 1A, 100 200 300 400 500 600 700 800 900 1000 RT FB2 165k 27.4k 8 LEDs I 43.2k UP TO LED (mA) 2MHz 3964 TA01b SYNC/CLKOUT 26V ISP2 2-WIRE SCL ISN2 I2C INTERFACE SDA PWMTG2 ADDR1 ADDR2 3964 TA01a INTVCC 3964fb For more information www.linear.com/LT3964 1
