Why is my MC14504B circuit acting strangely?

Question

Chip in Question: ON Semiconductor - MC14504B
Datasheet Link: https://www.onsemi.com/pdf/datasheet/mc14504b-d.pdf
Issue at Hand:
I am intending to use this chip alongside Arduino Mega 2560. When I bring Arduino pin High(5VDC) I was opening a relay. I had to change the relay to one that opens at around 7VDC. Because of this I am using the MC14504B to step up the voltage and open relay when set to high.

My understanding of the chip is that when you enter 5VDC into VCC and 9VDC into VDD, then apply a 5VDC(HIGH or 1) to one of the eight "IN" pins, the corresponding "OUT" pin should then be brought to HIGH or 1, at voltage applied to VDD.

In practice this is not the behavior I am experiencing. Measurements were made with Calibrated Keysight 3458A. Please see schematic and notes below.

I am not understanding why when I bring FIN to match VCC, why I am not getting the voltage at VDD off pin FOUT as described. I am using all the channels on this chip, but for ease of understanding made a sketch of the problem at hand.

I am using a total of 3 of these chips for (8x3) 24 Channels.

Can someone help me understand what I am doing wrong. I am fairly new and self taught to electronic engineering.

Answer 1

Consider all CMOS as an ideal switch with a resistor that is supply and temperature sensitive, ranging from 22 Ohms for lov voltage 74ALC 3.6V types to 1k max for 16V types.

Using Ohm's Law you can compute this but generally to avoid cross-conduction issues, the higher the voltage rating , the higher the RdsOn of the P/Nch FET outputs. For example at high temp Roh=(Vdd-Voh)/Ioh (output high) is almost 1k at 125 'C.

If you only need one output a low side NPN coil drive and diode is the easiest solution.

I'll bet you a dozen donuts the DCR of the relay is lower than the computed Roh of the CMOS.