CMOS protection networks?

[Chunkymonkey94]

What are they for?
How do you make one?
How would you use them with a CD4069U and CD4017BE IC?

 

[alec_t]

Try googling for 'cmos protection circuits'.

 

[audioguru]

The datasheet for most Cmos logic ICs has the schematic that shows the input protection parts.
Here is the schematic of a CD4069 inverter. It has 3 diodes and a resistor to clamp the input voltage from going too high.

 

[Chunkymonkey94]

The datasheet for most Cmos logic ICs has the schematic that shows the input protection parts.
Here is the schematic of a CD4069 inverter. It has 3 diodes and a resistor to clamp the input voltage from going too high.

I don't konw if it matters but what does the dotted line mean?

 

[audioguru]

I don't know if it matters but what does the dotted line mean?

Maybe there are a few diodes connected to taps on the resistor.

 

[Chunkymonkey94]

I'm sorry if I sound dumb but what does that mean?

 

[ronsimpson]

I'm sorry if I sound dumb but what does that mean?

I believe what AudioGuru is saying is that there might be 10 diodes on top and 9 resistors.

When you make a IC there are opportunities to make 'parts' that do not have names. In this case, I believe the two diodes and resistor are one part. There is a 100 ohm resistor from left to right. The diode connects to supply at the top. The bottom of the diode connect all along the resistor. You could think of it as 100 diodes connected every 1 ohms along the entire resistor.

 

[Roff]

I believe what AudioGuru is saying is that there might be 10 diodes on top and 9 resistors.

When you make a IC there are opportunities to make 'parts' that do not have names. In this case, I believe the two diodes and resistor are one part. There is a 100 ohm resistor from left to right. The diode connects to supply at the top. The bottom of the diode connect all along the resistor. You could think of it as 100 diodes connected every 1 ohms along the entire resistor.

Yeah, it is really a distributed diode. Attached is a drawing of how it is probably fabricated.