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SN74LVC1G3157: Slew rate requirement of SN74LVC1G3157

Prodigy 90 points

Replies: 2

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Part Number: SN74LVC1G3157

I am using SN74LVC1G3157 with Vcc = 3.3V

Page 3 of the datasheet recommends that the maximum of dt/dv = 10ns/V

However, I2C signal's falling time could be as long as 300ns, far exceeding the recommended maximum of dt/dv =10ns/V. The input signal slew rates matter for clocked flip flops or latches.

My questions are:
(1) Is  "the maximum of dt/dv =10ns/V" a hard requirement?
(2) What happens if my inputs do not meet this requirement of " the maximum of dt/dv =10ns/V"?

Thanks

  • Δt/Δv applies only to digital inputs, i.e., only to the S pin of this device.

    The A/B1/B2 pins can handle analog signals with any voltage at any speed.

    (For I²C, consider using a two-channel device like the TS3A5223.)

  • In reply to Clemens Ladisch:

    Hi Celi,

    The dv/dt spec represents the rate of change of the input voltage waveform during a logic transition (low-to-high or high-to-low).
    To avoid output-waveform abnormalities, input voltage transitions should be within the range set forth in the recommended operating conditions. (10ns/V for  SN74LVC1G3157).

    Regards

    Saminah