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TUSB1002: Question about the threshold of LFPS signal

Part Number: TUSB1002

Hello,

I have a question about the datasheet of TUSB1002.

I see the VRX-LFPS-DET-DIFF-PP has two value: 100mVpp (min) and 300mVpp (max). It mean: The design has only one Vthreshold and it between 100mVpp and 300mVpp or the design has two Vtheshold, the signal LFPS will be detected when it > 300mVpp, and won't be detected when it < 100mVpp?

I have this question because in the usb 3.1 specification, I think specification define two Vthreshold: The device explicitly supports USB 3.1 LFPS by detecting an idle state at the input and squelching the corresponding output to prevent unwanted noise from being redriven. When the differential input LFPS signal falls below the 100mVP-P threshold, the device squelches the output. When a differential LFPS signal above 300mVP-P (typ) is present at the input, the device turns on the corresponding output and redrives the signal.

Was I understood correctly? Please explain the detail to me!

Thanks and best regards.
Chau

  • Chau

    Your understanding is correct.

    I have this question because in the usb 3.1 specification, I think specification define two Vthreshold: The device explicitly supports USB 3.1 LFPS by detecting an idle state at the input and squelching the corresponding output to prevent unwanted noise from being redriven. When the differential input LFPS signal falls below the 100mVP-P threshold, the device squelches the output. When a differential LFPS signal above 300mVP-P (typ) is present at the input, the device turns on the corresponding output and redrives the signal.

    So when above 300mV peak to peak, input signal is passed to output.

    Thanks
    David
  • Hi David,
    Thanks you very much!
    Thanks
    Chau