This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

OPA4197: Input has protection to spikes and negative signal?

Genius 16019 points
Part Number: OPA4197
Other Parts Discussed in Thread: OPA197, OPA206

Tool/software:

Hi Experts,

Can you assist this query from customer?

They are in process of finding alternate for OP747ARZ (which is our current part). I found OPA4197ID (Texas part) as alternate, as in their existing design they have single source from 0 to 5V supply voltage, High pass RC filter (basically a differentiator) input to non-inverting pin, they see negative spikes with magnitude of around -4V at input (non-Inverting).

As datasheet says from absolute maximum rating Input voltage = –VS – 5 V to +VS + 5 V. Which means Input can withstand negative spikes even with single supply (0 to 5V) is this correct?

Query:
We would like to know whether the alternate part will withstand negative spikes even when it operates with single supply from 0 to 5V? As datasheet says Rail to Rail Input, correct me if I'm wrong Input can withstand negative spikes only when it operates with dual supply but not with single supply or the other way around where input can still withstand negative spikes even when it operates with single supply?

Thank you.

Regards,
Archie A.

  • Hi Archie, 

    The OP747ARZ's cross reference is the following. 

    https://www.ti.com/cross-reference-search/singlepart?searchTerm=OP747

    We would like to know whether the alternate part will withstand negative spikes even when it operates with single supply from 0 to 5V?

    For OPA197, the input signal pins are shown in the table below. For single supply rail, V- = GND, and the minimum Vcm input is approx. -0.5V, and input current is limited to ±10mA. The differential input signal is approx. 5V - GND + 0.2V = 5.2 V delta (max).  

     

    If you are using OPA206, then the input is protected from the negative transient spikes, and no additional external component protections are needed. 

    Please be aware the input Vcm mode for OPA206.

    BTW, all these products are 36V op amp, and the power supply rail may be on a low side.  

    What type of application is this? Please let me know.

    Best,

    Raymond