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SN74LV1T125: output impedance

Guru 20090 points
Part Number: SN74LV1T125
Other Parts Discussed in Thread: SN74LV4T125,

Hello,

Could you please let me know the output impedance of SN74LV1T125 and SN74LV4T125?

Our customer using these device with 60MHz signal and long cable.
Thus, there are some capacitance and slew rate is slow.
In customer estimation , the output impedance is 125ohm.
We would like to know their estimation is correct.

I appreciate it you would support this post.

Best Regards,
Ryuji

  • The worst-case output impedance can be computed from the worst-case output voltage with Ohm's law. For example, at VCC = 5 V, you get 0.55 V / 16 mA ≈ 34 Ω. (The actual impedance will be lower than the worst-case one.)

    Devices in the LVC family would have lower ouput impedance. If that is not enough, consider adding another line and using differential signals (e.g., LVDS).

  • As Clemens mentioned, the output impedance will depend on the supply voltage. 125 ohms is not an unreasonable output impedance for this device if it is operating at low voltage (1.8V supply).
  • Hello Clemens san, Emrys san,

    Thank you for the reply.
    I appreciate it if you would add the impedance information to the datasheet.

    Best Regards,
    Ryuji