TL074: TL074 OP output connect pull-high resistor and cap to ground

Leo Chen

Prodigy 50 points

Part Number: TL074

In my application, Tl074 output will have a pull-high resistor 2k to 5v, and 0.1uF to GND.

From testing result, the output voltage signal and gain is correct.

But is there exist any risk when I use with these pull-high resistor 2k and Cap 0.1uF for OP-amp output ?

over 7 years ago

0 Ron Michallick over 7 years ago

TI__Guru**** 157416 points

Leo,

I see no benefit for the pull up resistor. It would be best if +/-15V supply comes up first. 5V supply should power up last.
The capacitor will cause gain peaking , low phase margin and might even oscillate.

0 Leo Chen over 7 years ago in reply to Ron Michallick

Prodigy 50 points

Thanks for your reply,

Why it would be best if +/- 15v come up first, then 5v last ?

0 Ron Michallick over 7 years ago in reply to Leo Chen

TI__Guru**** 157416 points

Leo,

If 5V came up first then current would flow into TL074 output (from +5V supply) to +15V supply. The current level is low enough to not cause issue. Nevertheless it would be better if this current never occurred.

Amplifiers

Amplifiers forum

TL074: TL074 OP output connect pull-high resistor and cap to ground