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TPS7B88-Q1: Noise vs frequency wave form

Kazuki Kuramochi
Genius 10625 points
Part Number: TPS7B88-Q1


Hello Expert,

I have question for this device.
I confirmed noise vs frequency performance at datasheet.
Datasheet's graph seems different against general LDO curve.
General LDO's curve showed that 1/f noise is start from really low frequency to 1k~10k.
However, this device's 1/f noise start from 1kHz and corner is around 200kHz.
Also, it has plateau area from low frequency to 1kHz as like as white noise.

Would you tell me why this device has unique noise vs frequency curve?


Best regards,
Kazuki Kuramochi 

  • +1
    TI__Expert 6799 points

    Hello Kazuki, 

    In Figure 6-11. of the TPS7B88-Q1, Noise vs Frequency, graph from 10Hz to roughly 10kHz is dominated by the Voltage reference noise. In other LDOs with low noise features, this region drops off due to either internal or external CNR cap. This is due to the architecture of the low noise LDOs to allow this reduction in noise and drop-off in this region in comparison to the plateau area that you are referring to. However, the noise in the TPS7B88-Q1 is a more typical graph for the noise graph of an LDO.

    Let me know if you have any further questions, comments, or concerns. 

    Thank you, 

    McKyla