On Page 7 of the datasheet for M74HC590
It uses a CL (pF)
At the bottom of Page 8 is the test circuit which shows where the CL(pF) goes, in regards to a circuit diagram, but I don't understand that circuit diagram. Is the D.U.T. the chip they are testing?
For context what I'd like to do when I get these chips is put 4 of them in series to count the amount of time it takes sound to go from one ultrasonic transducer to another with as high of accuracy as I can.
So I can calculate the speed of air traveling through a pipe so I can know the volume of air traveling through it, In the volume of 1-200 Liter per minute hopefully with a resolution greater than .1 LPM through a 1" PVC pipe.
I could probably go smaller but I am limited by the blower blowing the air to have at least 2 Kpa with a minimum of 200 LPM and I don't have any information on how the flow will drop as the pressure increases. So I'm worried if I go too small on the pipe I'll get to much of a pressure drop before I get to the outlet where I need that much pressure.
240 LPM @ 32k RPM 4.5A 0 Pressure vs At Zero flow 5Kpa of pressure 1.6A 36k RPM Is the blower output