Its 6V to 100V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial and architectural lighting. The LT3756 uses an external N-channel MOSFET and can drive up to 20 1A white LEDs from a nominal 12V input, delivering in excess of 70 watts. It incorporates a high-side current sense, enabling it to be used in boost, buck, buck-boost or SEPIC and flyback topologies. The LT3756 can deliver efficiencies of over 94% in boost mode, eliminating any need for external heat sinking. A frequency adjust pin permits the user to program the frequency between 100kHz and 1MHz, optimizing efficiency while minimizing external component size and cost. Combined with a 3mm x 3mm QFN or a thermally enhanced MSOP-16 package, the LT3756 offers a very compact 70-watt LED driver solution.
The LT3756 uses True Color PWM™ dimming, delivering constant LED color with dimming ranges up to 3,000:1. For less demanding requirements, the CTRL pin can be used to offer a 10:1 analog dimming range. Its fixed frequency, current mode architecture ensures stable operation over a wide range of supply and output voltages. A ground referenced voltage FB pin serves as the input for several LED protection features, making it possible for the converter to operate as a constant-voltage source.
Two versions of the LT3756 are available. The standard LT3756 offers an Open LED Status pin, and the LT3756-1 replaces the Open LED Status pin with a frequency synchronization pin.
| Summary of Features: LT3756/-1 | |
 | 3000:1 True Color PWM Dimming |
| Wide Input Voltage Range: 6V to 100V |
| Output Voltage Up to 100V |
| Constant-Current & Constant-Voltage Regulation |
| 100mV High Side Current Sense |
| Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, SEPIC or Flyback Topology |
| Adjustable Frequency: 100kHz to 1MHz |
| Programmable Undervoltage Lockout with Hysteresis |
| Open LED Status Pin (LT3756) |
| Frequency Synchronization (LT3756-1) |
| PWM Disconnect Switch Driver |
| CTRL Pin Provides Analog Dimming |
| Low Shutdown Current: <1uA |
| Programmable Soft-Start |
| Thermally Enhanced 16-Lead QFN 3mm × 3mm Package |
