SN74HC164: fake SN74HC164DR with no TI logo printed?

Sorry for the late response, I was away. The clock variable is sent from CD4046, I´m attaching 2 images from clock input pin

SN74HC164 is powered with 5V

I´m using a CD4046 because i need to send a variable clock and the reason is I´m testing a noise circuit with this example, it works well with previews SN74HC164DR

Your oscilloscope might show a wrong rise/fall time because of the sample rate. Please zoom in on an edge to measure it properly.

What exactly is wrong? Please show an oscilloscope trace of the CLK and B inputs and the QA output that you think is wrong.

Here is a zoom and a short video from oscilloscope from CLK pin, B input is 5V and Q´s are not output signal

seems last video cant be reproduced

The problem I´m sending a variable clock freq from 4046 but SN74HC164DR outputs are not responding

Hi Luis,

This does look like you are right near the edge of a slow input transition rate for this device. I am not very familiar with the PLL device but you should try adjusting the values of the resistor divider to speed up the edges.

Best,

Malcolm

I´ve tried the CD74ACT164M96 instead and it works too, it has no problem reading 4046 clock, it seems new SN74HCS164 version have issues reading 4046 clock, anyway I hope this post helps other users