The LT?3598 is a fi xed 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.
Additional features include programmable overvoltage
protection, switching frequency synchronization to an
external clock, LED current derating based on junction
temperature and/or LED temperature, LED string disable
control, OPENLED alert pin and output voltage limiting
when all LED strings are disconnected. The LT3598 is
available in a thermally enhanced 24-pin (4mm × 4mm)
QFN package.