LT3598 Demo Board

Discussion in 'General Electronics Chat' started by ELECTRONERD, Aug 7, 2009.


    Thread Starter AAC Fanatic!

    May 26, 2009

    I just received the LT3598 demo board from Linear Technology and I have a few questions. Below you'll find the LT3598 datasheet and also the Demo circuit quick start guide.

    In the Quick Start Guide, they say to connect the PWM pin to VIN. I'm wondering how I can adjust the PWM? In the schematic if I put another resistor from the CTRL pin to ground it would form a voltage divider. Thus, varying voltage. Or, would I put a resistor from the PWM pin to ground? Would this adjust the PWM? Also, what are the OPENLED, and SYNC pins for?

  2. Ron H

    AAC Fanatic!

    Apr 14, 2005
    The quickstart guide says
    The PWM signal cannot be a DC level, unless you want the LEDs full on or full off. You have to provide a variable duty cycle pulse waveform (PWM) to vary the LED brightness. You can generate this with a circuit such as SgtWookie's Simple PWM Circuit.
    From the datasheet: