I was looking for an 8-bit parallel to serial shift register to use in a project I am making. Initially, I thought that the 4021 would work perfectly for what I need, however, after looking at the datasheet I am a little confused.
Below is a screen-grab of the TI Datasheet (http://www.ti.com/lit/ds/symlink/cd4021b-q1.pdf) (pg 6). I am confused as to why the maximum clock input frequency is listed as a minimum of 3 MHz.
I have never heard of an IC having a minimum input frequency so wondered if the problem is more just my understanding of what the information is telling us. At the top of the datasheet it also talks about the clock being run at a typical frequency of 12 MHz, which is a lot higher than I was planning to run it at.
As an alternative I found the 74HC165 (https://assets.nexperia.com/documents/data-sheet/74HC_HCT165.pdf) and any insight into if this is better or not would be appreciated as well.