Description

The LT®3517 is a current mode DC/DC converter with an internal 1.5A, 45V switch specifically designed to drive LEDs. It operates in boost, buck mode, and buck-boost mode. The LT3517 combines a traditional voltage loop and a unique current loop to function as a constant-current source or constant-voltage source. With a programmable switching frequency, the external components can be optimized for efficiency or component size.

Specifications and Features

• 5000:1 True Color PWMTM Dimming Ratio
• 1.5A, 45V Internal Switch
• 100mV High Side Current Sense
• Open LED Protection
• Adjustable Frequency: 250kHz to 2.5MHz
• Wide Input Voltage Range: Operation from 3V to 30V Transient Protection to 40V
• Operates in Boost, Buck Mode, and Buck-Boost Mode
• Gate Driver for PMOS LED Disconnect*
• Constant-Current and Constant-Voltage Regulation
• CTRL Pin Provides 10:1 Analog Dimming
• Low Shutdown Current: <1μA
• Available in (4mm × 4mm) 16-Lead QFN and 16-Pin TSSOP Packages

Application Scenarios

• Display Backlighting
• Automotive and Avionic Lighting
• Illumination
• Scanners

Comparison

- High efficiency with programmable switching frequency

- Versatile operation modes: boost, buck, and buck-boost

- Requires additional external components for operation