• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 965 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TL972: Is TL972 suitable in below use case?

Wayne Wang20
Expert 4360 points
Part Number: TL972
Other Parts Discussed in Thread: INA163

Hi team,

My customer has a requirement for a low noise audio amp. The amp is used to convert the differential signal from MIC to single ended signal. The gain is set to 1V/V and the input signal is -41dBv, 100Hz~10kHz.

Customer required that the amp total noise is under -106dBV. And the SNR needs to be higher than 65dB when the input is -41dBV. The power supply of the amp is single supply @3~3.3V.  Do you think the TL972 is suitable? If not, do you have any other recommendation? Thanks.

Best regards,

Wayne

 

  • 0
    TI__Guru** 100555 points
    Hi Wayne,

    TL972 might be a good option. It is Rail-to-Rail output so there is no limitation on output range, as for the input the Vicm is (Vcc-)+1.15 to (Vcc+)+1.15, thus for 3V supply, input range is 0.7V and if input is -41dBv then it should be OK.
    The required bandwidth is also OK for TL972 and noise voltage spec is 4nV/rHz.
    There is PSPICE and TINA model available for this device in case some analysis is needed.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    TI__Expert 4360 points

    Hi Ivan,

    Thanks for your reply. I have built a TINA model for the TL972 according to customer's design. Please see the attached for this model.

    For MIC input, the single ended input  is -41dBV and the differential input is -35dBV. So could you please help calculate the total noise of TL972 to see if the total noise can be lower than -106dBV? Thanks.

    Best regards,

    Wayne

    TL972.TSC

  • 0 in reply to Wayne Wang20
    TI__Guru** 100555 points
    Wayne,

    There is Noise Analysis tool in TINA, under toolbar options: Analysis -> Noise Analysis...
    In addition, you can take a look at online training on this matter from TI Precision Labs: training.ti.com/ti-precision-labs-op-amps-noise-1
    It explains noise, how to calculate RMS and Total Noise as well as TINA simulation with noise simulation.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0
    Guru 140200 points

    Hi Wayne,

    I would take the INA163:

    It's hard to beat its noise performance!

    What microphone are we talking about? What is its impedance?

    Kai