OPA817: OPA817

Federico Moran

Part Number: OPA817

Tool/software:

Hi, I have read the answers and looked at the datasheet, but I still have questions about the PD pin in the opa817.

I see Table 7.5 and understand that I need to apply 5V to the PD pin to enable the op-amp. However, the table indicates that the op-amp consumes more current when it is in shutdown mode (with less than 2V on the PD pin). So the current consumption is higher when the PD pin has less than 2V, which mens the op amp its active.

This part of the datasheet is also wrong ? Because i have read in the forum that the table 6.1 in the datasheet have errors.

So wich voltaje should i put on the PD pin to enable de op amp ?

11 months ago

+1 Clemens Ladisch 11 months ago

Guru 317370 points

This specifies only the current that flows into or out of the /PD pin. The current is higher for low voltages because of the internal pull-up resistor.

0 Federico Moran 11 months ago in reply to Clemens Ladisch

Prodigy 10 points

Oh perfect, I hadn't read it properly. So, to enable the op amp, I connect the PD to Vs. But if I leave the PD pin floating, the op amp is also activated, right?

Thank you very much for the help.

+1 Alec Saebeler 11 months ago in reply to Federico Moran

TI__Mastermind 23049 points

Hello Federico,

The OPA817 has an internal pull-up resistor, 2MOhms. This resistor allows you to float the PD input.

Please be aware the disable threshold when Vs+ = 5V is 3V and below, so you should confirm the amplifier is on and operating with the correct quiescent current when debugging. While unlikely, a floating voltage is less absolute than a strict voltage.

In short, yes you can float the PD-bar pin.

Best,

Alec

0 Federico Moran 11 months ago in reply to Alec Saebeler

Prodigy 10 points

Thank you very much for the help Alec!

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OPA817: OPA817