LM2759: is minimum delay required between two successive flash enables ??

vignesh chandrasekaran

Part Number: LM2759
Other Parts Discussed in Thread: LM3643, LM36010, LM36011, LM3644

we are working on the LED driver LM2759, in our application we tend to use FLASH mode continuously,in datasheet we didn't find any details, regarding minimum delay required between successive flash enables using strobe pin, is there any delay required or there are no constraints ??

over 4 years ago

0 Sean Zhou over 4 years ago

TI__Mastermind 22745 points

Hi Vignesh,

I would prefer to suggest with the new device: LM3643/LM3644/LM36010/LM36011 with IR mode, there is an application note that give out the detail time specification that can help with you.

Sean

0 vignesh chandrasekaran over 4 years ago in reply to Sean Zhou

Prodigy 70 points

thanks for your reply sean, but we already on fabrication we can't change part so we require timing details of LM2759.

0 Sean Zhou over 4 years ago in reply to vignesh chandrasekaran

TI__Mastermind 22745 points

Hi Vignesh,

I'm sorry that we don't have the data on hand that you need, but you can test with your board and if you have found something wrong with your board, please let me know.

Sean

0 vignesh chandrasekaran over 4 years ago in reply to Sean Zhou

Prodigy 70 points

ok sean,
by the way, do i get any minimum interval value from your previous testings or evm boards ??
i also went through some question related to toggling strobe pin at 30HZ, is it working case ? because if it is so i will go ahead with that value.
https://e2e.ti.com/support/power-management/f/196/t/566733

one more thing, i found that internal clock is 1MHz can we derive anything with this like sampling rate of strobe input ??

regards,
vignesh

0 Sean Zhou over 4 years ago in reply to vignesh chandrasekaran

TI__Mastermind 22745 points

Hi Vignesh,

Since there is about a 2.5ms delay between the strobe pin going high and the current being up and regulating (turn on delays and current ramping time), so this timing must be accounted for in your application, you need to consider this time for higher frequency.(not exceed 400Hz)

Sean

Power management

Power management forum

LM2759: is minimum delay required between two successive flash enables ??