DESCRIPTION

The LT®3598 is a fixed frequency step-up DC/DC converter designed to drive up to six strings of LEDs at an output voltage up to 44V. LED dimming can be achieved with analog dimming on the CTRL pin, and with pulse width modulation dimming on the PWM pin. The LT3598 accurately regulates LED current even when the input voltage is higher than the LED output voltage. The switching frequency is programmable from 200kHz to 2.5MHz through an external resistor.

FEATURES

■ True Color PWM™ Dimming Delivers Up to 3000:1 Dimming Ratio
■ Drives Six Strings of LEDs at Up to 30mA
■ 1.5% Accurate LED Current Matching
■ Wide Input Voltage Range: 3.2V to 30V
■ Output Voltage Up to 44V
■ Regulates Current Even When VIN > VOUT
■ Disconnects LEDs in Shutdown
■ Programmable Open LED Protection (Regulated)
■ OPENLED Alert Pin
■ Programmable LED Current Derating
■ Adjustable Frequency: 200kHz to 2.5MHz
■ Synchronizable to an External Clock
■ Parallel Channels for Higher Current per LED String
■ Thermally Enhanced 4mm × 4mm QFN and 24-Lead TSSOP Packages

APPLICATIONS

■ Notebook Computer Display
■ Medium Size Displays
■ Automotive LCD Display