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SN74HC191: On the internal structure of parts

Part Number: SN74HC191

Hi,Please tell me.

Is the internal structure of the following 4 pins pullup?
Or is it pulldown?

Also,What is the response speed of each pin?

1.QA~QD output pin

2.CLK

3./LOAD

4./CTEN

best regards,

otake

  • Hello Otake-san,
    Pull-up and pull-down are not architecture types for CMOS devices. There are three common output types: push-pull, open-drain, and 3-state. There are two common input types: standard CMOS, Schmitt-trigger

    The SN74HC191 has balanced push-pull outputs (as indicated by the IOL values in teh electrical characteristics table -- IOH = -5.2mA, IOL = 5.2mA). This is true for all output pins, including QA~QD.

    The SN74HC191 has standard CMOS inputs, as indicated by the VIH and VIL listed in the recommended operating conditions table. This is true for all input pins, including CLK, /LOAD, and /CTEN.

    The response time of the device is described in the timing requirements on the datasheet. For example, if you need to know the time for an input to go from the CLK pin to the output (with Vcc = 5V, TA = 25C), the propagation delay can be found on page 8 of the datasheet as (typical) 31 ns.
  • Hi,Thank you for your answer.

    I missed the speed parameter of the data sheet.
    I solved it, thank you.

    otake