Question: About the minimum value of RA of NE555.

Toshiya Hiramatsu

Intellectual 630 points

Other Parts Discussed in Thread: NE555

Hi,

I have a question about NE555.

What is minimum value of "RA" at figure-12 in the data sheet?
(for reference).
Or,is "RA=230Ohm" no problem?

Could you please teach me?
Thanks in advance,

Toshiya

over 15 years ago

0 Chris Cockrill over 15 years ago

TI__Mastermind 46480 points

The min recomended value is 1K. It can operate with lower values but the range adjustment will be decreasing. I dont know what the absolute minimum is.

0 Toshiya Hiramatsu over 15 years ago in reply to Chris Cockrill

Intellectual 630 points

Chris-san

Thanks for your prompt response and explanation.
It is useful for me.

Regards

Toshiya

0 Ron Michallick over 15 years ago in reply to Chris Cockrill

TI__Guru**** 165146 points

The Ra & Rb resistors should limit the discharge pin current to less than 100mA.

0 Toshiya Hiramatsu over 15 years ago in reply to Ron Michallick

Intellectual 630 points

Hello! Ron-san,

Thanks for your explanation.
"100mA" is useful for me.

Regards

Toshiya

Clock & timing

Clock & timing forum

Question: About the minimum value of RA of NE555.