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SN65LVCP22: Basic questions

Takumi Suzuki1
Mastermind 8490 points
Part Number: SN65LVCP22

Hi,

Let me ask you some basic questions as below.

Q1) unusued IN+/IN- pins

Will you tell me how to handle these pins in case unusing?

Is it possible to leave "open"?

Q2) EN0/EN1

In case of using these pins with "H" fixed, is it possible to connect 3.3V directly?

Because there are 400ohm and 300Kohm resisters at the input.

(Datasheet 3page, "equivalent input and output schematic diagrams") 

Q3) SEL0/SEL1

I would like to use both pins with "L" fixed.

In this case, I suppose we can connect both pins to GND directly according to the equivalent schematics.

Or is it possible to leave both pins "Open"?

Will you give me your advice?

Thank you for your support!

Best Regards,

Takumi

  • +1
    TI__Guru**** 157496 points

    Takumi-san

    Q1) unusued IN+/IN- pins

    Will you tell me how to handle these pins in case unusing?

    Is it possible to leave "open"?

    For these unused differential inputs I would recommend to tie the "+" input to VCC and the "-" input to GND.

    Q2) EN0/EN1

    In case of using these pins with "H" fixed, is it possible to connect 3.3V directly?

    Because there are 400ohm and 300Kohm resisters at the input.

    (Datasheet 3page, "equivalent input and output schematic diagrams") 

    I would recommend connect to 3.3V through a 1k resistor.

    Q3) SEL0/SEL1

    I would like to use both pins with "L" fixed.

    In this case, I suppose we can connect both pins to GND directly according to the equivalent schematics.

    Or is it possible to leave both pins "Open"?

    I would recommend connect to GND directly.

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Mastermind 8490 points

    Hi David-san,

    Thank you for your reply !

    Let me confirm one point about Q2.

    Why do you recommend to use 1K resister?

    I suppose the reason that as there is "zener" diode in front of the input, 1K resister will guard from rush current.

    Is my idea correct?

    Thanks and Regards,

    Takumi

  • +1 in reply to Takumi Suzuki1
    TI__Guru**** 157496 points

    Takumi-san

    Correct, 1k will act as a current limiting resistor.

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Mastermind 8490 points

    David-san,

    Thank you very much for your reply !

    I understood.

    Regards,

    Takumi