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TLV9062: Need assistance in a problem with triangle wave generator

Part Number: TLV9062
Other Parts Discussed in Thread: TINA-TI, TLV3501, OPA365

Hi,

Good day. I hope you are well.

Our customer have a question regarding the related E2E post. On the basis of the advise provided, they replaced the 2-channel FET op-amp(TLV9062) with one push-pull comparator(TLV3501) and a FET output Op-amp (OPA365). Request you to refer to the attached image of the schematic and output generated using TINA-TI.


The square wave transition is perfect. But in the triangle wave part, there is some jitter at the extreme points of the plot (marked in red). Can you please suggest a way to remove this disturbance. Their application's response will be affected tremendously because of this slight distortion.

Thank you.

Regards,

Cedrick

  • Hi Cedrick,

    a simple low pass filter does the trick:

    cedrick_tlv9062.TSC

    The reason for the spike is the steep edge coming from the fast comparator and rushing through C2 directly to the output of OPAmp. These spikes running through the phase lead capacitance (here integration capacitance) can often be seen in inverting OPAmp circuits. The RC low pass filter formed by R5 and C3 slows down the edge and minimizes this unwanted "punch through" :-)

    Kai

  • Reducing C3 a bit also works well and leaves the square wave almost unchanged:

    You have to find a suited compromise.

    Kai

  • Former Member
    0 Former Member

    Hi Kai,

    Thank you very much for taking a look at this!

    Hi Cedrick,

    Please let us know if these suggestions are acceptable to the customer.

    Regards,
    Daniel