noise of SSM2019

Dear Sir/Madam,

We are using SSM2019 Self-Contained Audio Preamplifier.

We have observed the noise on our system. Pls refer to the attached file.

sheet1. Our test circuit diagram.
sheet2. Waveform which the noise occurred.
sheet3. Normal waveform.

It is irregularly-recurring noise and the repetition is not regular.
Quantity of the device that this phenomenon occurred :9pcs/460pcs

We would like to know the cause of this noise.

It would be greatly appreciated if advice could be gotten.

Sincerely yours,
Kou

ssm2019.pptx
  • Dear Sir/Madam,

    I am still waiting for your reply,would appreciate it if you could expedite your response to us.

    Thank you.

    Sincerely yours,
    Kou

  • 0
    •  Super User 
    on Feb 20, 2014 8:01 AM

         Hello Kou,

         The two noise pulses shown in slide 2 appear to be 20mS apart.  Could they be related to the 50 Hz line frequency?  Perhaps some nearby machinery, etc. is intermittently generating noise.

         Best regards,

         Bob

  • Hello Bob,

    Thank you for your reply.

    Noise is irregularly-recurring noise and the repetition is not regular.

    It's random noise,seems like a pop-corn noise...

    Best regards,
    Kou

  • 0
    •  Analog Employees 
    on Feb 20, 2014 6:10 PM

    Hello Kou,

    From page 1 of your slides, it appears that you are not applying any local power supply decoupling to the SSM2019. Is this the case? Please connect 1 uF between each power pin and GND, as close to the power pin as possible. This type of decoupling is best practice, and is part of the circuit when we measure noise performance for the datasheet. I apologize that this is not described in the datasheet. Please let us know if this has any affect on your noise measurements.

    Best regards,

    Coleman

  • Hello Coleman-san,

    Thank you for your reply and info.

    We connected the 1uF capacitor, and checked noise.

    Pls refer to the attached file again.

    Page4. The phenomenon has not changed.
    Page5. This shows the noise wave of another chip.

    Do you have any ideas?.

    Thank you again.

    Best regards,
    Kou