LM3559: LED strobe light function driver via 2x LED channels

Hi Leo,

    I'm not clear about your set up, do you mean you connect a LED to LED1 and one LED to LED2 separately? Maybe you can provide a schematic for a different setup. I can try to understand the problem.

BR

Sean

Hi Sean,

yes in my first case I connected 1x LED to LED1 & it works just fine with expected current consumption of 110mA. Next I tried connecting 1x LED to both LED1 & LED2, I noticed the current consumption is lower than I've expected. So my question is such connection valid? To have both LED1 & LED2 pin supplying current to drive 1 single LED as output.

Regards,

Leo 

Hi Leo,

    Have you tried to test whether the 'LEd2" channel works fine or not? if you tested the "LED2" is ok and then try to test with both "LED1" and "LED2" together.

BR

Sean

Hi Sean,

Yes I've tried the testing both channels simultaneously & it works just fine in terms of output LED brightness comparing to setup of 110mA load on single channel. But as I've mentioned the current sink observed still in the range of 70mA although i'm setting both LED1 & LED2 at 55mA to supply to a single output. 

Regards,
Leo

Hi Leo,

     It is really strange, have you try with other current regs? For example to change to above or below 55mA? Or is there any fault from the regs?

BR

Sean

Hi Sean,

I'll try to simulate result again using EVM. Can you try to validate on your end using an EVM to determine what's the expected current consumption of device based on the settings I've mentioned above? Thanks.

Regards,

Leo

Hi Leo,

    Please provide the regs list and schematic, I'd like to check your regs and schematic first.

BR

Sean