Its 4.5V to 40V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial and architectural lighting. The LT3755 uses an external N-channel MOSFET and can drive up to 14 1A white LEDs from a nominal 12V input, delivering in excess of 50 watts. It incorporates a high-side current sense, enabling it to be used in boost, buck, buck-boost or SEPIC and flyback topologies. The LT3755 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 package, the LT3755 offers a very compact 50 watt LED driver solution.
The LT3755 uses True Color PWM™ dimming, which delivers constant LED color with dimming ranges of up to 3,000:1. For less demanding dimming requirements, the CTRL pin can be used to offer a 10:1 analog dimming range. Its fixed frequency, current mode architecture offers 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.
| Summary of Features: LT3755/-1 | |
 | 3,000:1 True Color PWM Dimming |
| Wide Input Voltage Range: 4.5V to 40V |
| Output Voltage Up to 60V |
| Constant-Current and 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 (LT3755) |
| Frequency Synchronization (LT3755-1) |
| PWM Disconnect Switch Driver |
| CTRL Pin Provides Analog Dimming |
| Low Shutdown Current: <1uA |
| Programmable Soft-Start |
| Thermally Enhanced 16-Lead QFN (3mm × 3mm) Package |
