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[ TL974-Q1 ] SVR (Supply-voltage rejection ration) characteristics

Kenichiro
Mastermind 9165 points

[ TL974-Q1 ] SVR (Supply-voltage rejection ration) characteristics

Hi,

Can you please let me know the frequency condition for the specification of SVR (Supply-voltage rejection ratio)? From the drawing below, seems it's for 10KHz. Also, if customer ask this performance under different condition, can you support this inquiry?

* VCC+=5V, VCC-=0V

* room temp.

* Freq. = 1KHz

(Freq. response from 100Hz to1MHz)

Thank you for your support in advance.

Regards,

Ken

  • 0
    TI__Guru*** 140006 points
    Ken,

    The data sheet SVR is for both supply pins at DC ( 0 Hz ).

    The typical chart does not state the supply rail. Therefore it defaults to the positive supply in a single supply setup.

    The customer's desired +2.5V / 0V power does not meet the VCC requirements for the device.
    VCC recommended range is 2.7V to 12V
  • 0 in reply to Ron Michallick
    Mastermind 9165 points

    Hi Ron,

    Many thanks for your reply!

    First, my original post had typo and I already modified it(see red above).

    Second, let me try to understand your description.

    SVR characteristic in the datasheet is "DC SVR", so power supply to Opamp is not modulated (no noise injection).

    "AC SVR" has not been specified, reference chart only.

    Is my understanding correct?

    Then, don't you have a AC PSRR result for condition below?

    * VCC+=5V, VCC-=0V

    * room temp.

    * Freq. = 1KHz

    (Freq. response from 100Hz to1MHz)

    Thanks,

    Ken

     

    Reference: Analog Dialogue, Simple Op Amp Measurements from Analog Devices

    http://www.analog.com/library/analogDialogue/archives/45-04/op_amp_measurements.html

  • 0 in reply to Kenichiro
    TI__Guru*** 140006 points
    Ken,

    Yes, your understanding is correct.

    The data chart is typical behavior matches your setup, 5V supply. 1 kHz is 80dB.
    At 100Hz, the PSRR would be barely above 80dB.

    The data sheet and production test only guarantee the DC performance for SVR (PSRR)
    SVR and PSRR are the same test except SVR is DC and PSRR includes AC frequency