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SN74HC14: Which model is better to simulate SN74HC14 made by RFAB?

Kazuya Nakai59
Guru 20650 points
Part Number: SN74HC14
Other Parts Discussed in Thread: SN74HCS14

Hello guys, 

One of my customers said us that the output drive current capability of SN74HC14 made by RFAB is higher than one made by other FAB.
They want to simulate SN74HC14 made by RFAB using PSpice for TI for their design.
At this moment, they have the following question as the follow. Could you please give me your reply?

Q.  Which model is better to simulate SN74HC14 made by RFAB? Is it SN74HC14 SPICE model or SN74HCS14 SPICE model?

Your reply would be much appreciated.

Best regards,
Kazuya.

  • 0
    TI__Guru* 96711 points

    Hello Kazuya-san,

    Neither SPICE behavioral model will provide perfectly accurate data - they are only tools for basic circuit construction and should not be used as a replacement for proper design using the datasheet limits.

    For the best results I would recommend simulating input impedance and output behavior with an IBIS simulator and the SN74HCS14 IBIS model.

  • 0 in reply to Emrys Maier
    Guru 20650 points

    Hello Emrys,

    Thank you very much for your reply.
    I understood.

    Could I ask you an additional question as the follow?

    Q. Has SN74HC14 PSpice for TI model been recently updated for SN74HC14 made by RFAB?

    Thank you again and best regards,
    Kazuya.

  • 0 in reply to Kazuya Nakai59
    TI__Guru* 96711 points

    No, but the PSpice for TI model should not be expected to provide a precise representation of the device -- these are simple models provided for customers to observe functionality, basic input impedance, and basic output drive strength. Precision thresholds, timing, and input / output behaviors are not modelled.

  • 0 in reply to Emrys Maier
    Guru 20650 points

    Hello Emrys,

    Thank you very much for your reply.
    The customer understood what you said.

    At this moment , the customer has an additional question as the below. 
    Could you please give me your reply for them?

    Q. How about IBIS model?
         Has SN74HC14 IBIS model been recently updated for SN74HC14 made by RFAB?

    Thank you again and best regards,
    Kazuya.

  • 0 in reply to Kazuya Nakai59
    TI__Guru* 96711 points

    Hello Kazuya-san,

    No, and it will not be for quite some time. Not all devices are manufactured in RFAB, and until they are, both types of devices could be received by a customer.

    I would recommend that they design to the datasheet limits rather than the typical operating characteristics.

  • 0 in reply to Emrys Maier
    Guru 20650 points

    Hello Emrys,

    Thank you very much for your strong supports.
    They understood what you said.
    Also they have a new question about SN74HC14 made by RFAB as the follow. If I should ask on another thread, please let me know?

    Q.
    They are well aware that there is no specification difference between SN74HC14 new datasheet (version SCLS085K) and the old datasheet (version SCLS085J). But they would like to know if SN74HC14 made by RFAB has any difference of characteristics which are not shown in the device datasheet from the device made by other factories because once they know that, they can take care of that in their next design.
    They would like to know whether the following their thought is correct or not. Could you please give me your reply?

    RFAB SN74HC14 case
    1. The output peak current is larger than other FAB one.
    2. The output raise/fall time is faster than other FAB one.
    3. The propagation delay is smaller than other FAB one.
    4. The peak current of shoot through from VCC to GND is larger than other FAB one.

    Thank you again and best regards,
    Kazuya.

  • 0 in reply to Kazuya Nakai59
    TI__Guru* 96711 points

    Hello Kazuya-san,

    I would recommend that this customer reach out to their TI sales team to get a data packet on the new device as these are not the type of details that can be provided on a public forum.

  • 0 in reply to Emrys Maier
    Guru 20650 points

    Hello Emrys,

    Thank you very much for your strong supports.
    I understood. I will ask TI sales about the data.

    Thank you again and best regards,
    Kazuya.