Datasheet LT3755, LT3755-1, LT3755-2 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 40VIN, 75VOUT LED Controllers |
| Pages / Page | 28 / 1 — FEATURES. DESCRIPTION. 3000:1 True Color PWM™ Dimming. Wide Input Voltage … |
| Revision | E |
| File Format / Size | PDF / 509 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. 3000:1 True Color PWM™ Dimming. Wide Input Voltage Range: 4.5V to 40V. Output Voltage Up to 75V
Model Line for this Datasheet
- LT3755EMSE#PBF LT3755EMSE#TRPBF LT3755EMSE#WPBF LT3755EMSE#WTRPBF LT3755EMSE-1#PBF LT3755EMSE-1#TRPBF LT3755EMSE-1#WPBF LT3755EMSE-1#WTRPBF LT3755EMSE-2#PBF LT3755EMSE-2#TRPBF LT3755EMSE-2#WPBF LT3755EMSE-2#WTRPBF LT3755EUD#PBF LT3755EUD#TRPBF LT3755EUD-1#PBF LT3755EUD-1#TRPBF LT3755EUD-2#PBF LT3755EUD-2#TRPBF LT3755HMSE-2#PBF LT3755HMSE-2#TRPBF LT3755HMSE-2#WPBF LT3755HMSE-2#WTRPBF LT3755IMSE#PBF LT3755IMSE#TRPBF LT3755IMSE#WPBF LT3755IMSE#WTRPBF LT3755IMSE-1#PBF LT3755IMSE-1#TRMPBF LT3755IMSE-1#TRPBF LT3755IMSE-1#WPBF LT3755IMSE-1#WTRPBF LT3755IMSE-2#PBF LT3755IMSE-2#TRPBF LT3755IMSE-2#WPBF LT3755IMSE-2#WTRPBF LT3755IUD#PBF LT3755IUD#TRPBF LT3755IUD-1#PBF LT3755IUD-1#TRPBF LT3755IUD-2#PBF LT3755IUD-2#TRPBF LT3755JMSE-2#PBF LT3755JMSE-2#TRPBF LT3755JMSE-2#WPBF LT3755JMSE-2#WTRPBF
Text Version of Document
LT3755/LT3755-1/LT3755-2 40VIN, 75VOUT LED Controllers
FEATURES DESCRIPTION
n
3000:1 True Color PWM™ Dimming
The LT®3755, LT3755-1 and LT3755-2 are DC/DC control- n
Wide Input Voltage Range: 4.5V to 40V
lers designed to operate as a constant-current source for n
Output Voltage Up to 75V
driving high current LEDs. They drive a low side external n
Constant-Current and Constant-Voltage Regulation
N-channel power MOSFET from an internal regulated 7.15V n 100mV High Side Current Sense supply. The fixed frequency, current mode architecture n Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, results in stable operation over a wide range of supply SEPIC or Flyback Topology and output voltages. A ground referenced voltage FB pin n Adjustable Frequency: 100kHz to 1MHz serves as the input for several LED protection features, n Open LED Protection and also makes it possible for the converter to operate n Programmable Undervoltage Lockout with Hysteresis as a constant-voltage source. A frequency adjust pin n Improved Open LED Status Pin (LT3755-2) allows the user to program the frequency from 100kHz n Frequency Synchronization (LT3755-1) to 1MHz to optimize efficiency, performance or external n PWM Disconnect Switch Driver component size. n CTRL Pin Provides Analog Dimming The LT3755/LT3755-1/LT3755-2 sense output current at n Low Shutdown Current: <1µA the high side of the LED string. High side current sensing n Programmable Soft-Start is the most flexible scheme for driving LEDs, allowing n Thermally Enhanced 16-Lead QFN (3mm × 3mm) boost, buck mode or buck-boost mode configuration. and MSOP Packages The PWM input provides LED dimming ratios of up to n AEC-Q100 Qualified For Automotive Applications 3000:1, and the CTRL input provides additional analog
APPLICATIONS
dimming capability. All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 7199560 and 7321203. n High Power LED n Battery Chargers n Accurate Current Limited Voltage Regulators
TYPICAL APPLICATION 50W White Automotive LED Headlamp Driver Efficiency vs VIN
V 22µH IN 8V TO 100 40V 4.7µF 1M V 1M 4.7µF IN SHDN/UVLO FB 96 VREF 185k ISP 23.7k 332k LT3755-2 0.1Ω 1A CTRL 92 INTVCC 40.2k ISN GATE 100k 88 SENSE EFFICIENCY (%) OPENLED 0.015Ω 50W PWM LED SS 84 STRING RT PWMOUT VC GND INTVCC 0.01µF 28.7k 80 375kHz 0 10 20 30 40 10k 4.7µF VIN (V) 0.001µF 37551 TA01b 37551 TA01a Rev. E Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
FEATURES DESCRIPTION
n
3000:1 True Color PWM™ Dimming
The LT®3755, LT3755-1 and LT3755-2 are DC/DC control- n
Wide Input Voltage Range: 4.5V to 40V
lers designed to operate as a constant-current source for n
Output Voltage Up to 75V
driving high current LEDs. They drive a low side external n
Constant-Current and Constant-Voltage Regulation
N-channel power MOSFET from an internal regulated 7.15V n 100mV High Side Current Sense supply. The fixed frequency, current mode architecture n Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, results in stable operation over a wide range of supply SEPIC or Flyback Topology and output voltages. A ground referenced voltage FB pin n Adjustable Frequency: 100kHz to 1MHz serves as the input for several LED protection features, n Open LED Protection and also makes it possible for the converter to operate n Programmable Undervoltage Lockout with Hysteresis as a constant-voltage source. A frequency adjust pin n Improved Open LED Status Pin (LT3755-2) allows the user to program the frequency from 100kHz n Frequency Synchronization (LT3755-1) to 1MHz to optimize efficiency, performance or external n PWM Disconnect Switch Driver component size. n CTRL Pin Provides Analog Dimming The LT3755/LT3755-1/LT3755-2 sense output current at n Low Shutdown Current: <1µA the high side of the LED string. High side current sensing n Programmable Soft-Start is the most flexible scheme for driving LEDs, allowing n Thermally Enhanced 16-Lead QFN (3mm × 3mm) boost, buck mode or buck-boost mode configuration. and MSOP Packages The PWM input provides LED dimming ratios of up to n AEC-Q100 Qualified For Automotive Applications 3000:1, and the CTRL input provides additional analog
APPLICATIONS
dimming capability. All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 7199560 and 7321203. n High Power LED n Battery Chargers n Accurate Current Limited Voltage Regulators
TYPICAL APPLICATION 50W White Automotive LED Headlamp Driver Efficiency vs VIN
V 22µH IN 8V TO 100 40V 4.7µF 1M V 1M 4.7µF IN SHDN/UVLO FB 96 VREF 185k ISP 23.7k 332k LT3755-2 0.1Ω 1A CTRL 92 INTVCC 40.2k ISN GATE 100k 88 SENSE EFFICIENCY (%) OPENLED 0.015Ω 50W PWM LED SS 84 STRING RT PWMOUT VC GND INTVCC 0.01µF 28.7k 80 375kHz 0 10 20 30 40 10k 4.7µF VIN (V) 0.001µF 37551 TA01b 37551 TA01a Rev. E Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
