Analog Devices LT3599(Dual String)

Description

The LT®3599 is a fi xed frequency 2A step-up DC/DC converter designed to drive four strings of 120mA LEDs up to a 44V output voltage. The switching frequency is programmable from 200kHz to 2.1MHz through an external resistor.

LED dimming can be achieved with analog dimming on the CTRL pin, and with pulse width modulation dimming on the PWM pin. The LT3599 accurately regulates LED current even when the input voltage is higher than the LED output voltage.

Additional features include programmable LED current derating, switching frequency synchronization to an external clock, LED string disable control, OPENLED alert pin, SHORTLED alert pins and programmable maximumoutput voltage when all LED strings are disconnected.The LT3599 is available in the thermally enhanced 32-pin (5mm × 5mm) QFN and 28-pin TSSOP packages.

Features

• True Color PWMTM Dimming Ratio Up to 3000:1
• Drives Four Strings of LEDs at Up to 120mA
• ±1.5% Accurate LED Current Matching
• Wide Input Voltage Range: 3.1V to 30V
• Output Voltage Up to 44V
• Regulates LED Current Even When VIN > VOUT
• Disconnects LEDs in Shutdown
• Programmable Maximum VOUT (Regulated)
• Open/Short LED Protection and Fault Flags
• Programmable LED Current Derating
• Adjustable Frequency: 200kHz to 2.1MHz
• Synchronizable to an External Clock
• Analog Dimming Up to 20:1
• Programmable Input UVLO with Hysteresis
• Thermally Enhanced 32-Pin (5mm × 5mm) QFN and 28-Pin TSSOP Packages

Remarks

• For Inductor Values Refer Page no-10

Typical applications

• Desktop and Notebook TFT LCD Displays
• Automotive Navigation TFT LCD Displays

More information

• Datasheet
• IC product information