Comparison between two different muxes; listing of pros/cons

Thread Starter


Joined Oct 10, 2014
Hello everyone,

given my lack of expertise in the electronics domain, I hope a third party versed in the matter may guide me to a better understanding. Specifically, I wish someone stresses for me (something datasheet doesn't do for the everybody) what are the differences of performance that would make someone changes a mux of the old 4000 Series (e.g. CD4051; I think it was introduced by the now-extinct RCA company and numerous present companies still produce it using the same nomenclature as RCA; CD: CMOS+Digital and the serial number of the 4000 category) for a revised version like the DG509A (DG: Delay Generator tech?; I think the suffix "A" refers to either the inputs/outputs are buffered or not; here not buffered?). Regarding datasheets, I know the present DG509A was manufactured by MAXIM whereas the previous CD4051 manufacturer details are lost. It was physically replaced, but the circuit design still left traces of that change. Knowing better the reasons of such change may lead me to the right direction in understanding the whole circuit. Sadly, the circuit designers are gone and nobody near me can really help retracing the mental process of the circuit.

For as much I could collect information regarding the matter, it seems the older technology of the 4000 Series is less adapted to fast-processing ICs while the kinds like DG509A are better for that kind of job. The pinout is different between those two, so it might be a reason...for components setting optimization. For now, I leave to this and if clarifications are needed to purvey a better answer, I'll be there for this. I wished to be more detailed, but I am a tad at lost.



Joined Feb 24, 2006
The 4000 series was from the early 1970's. Its main features were a wide Vcc range from 3-18V at the expense of being slow. The DG prefix for analog switches doesn't stand for anything in particular and was originally used by Siliconix or Signetics. In any case as old parts become extinct it is common to replace their function in a design with more modern parts. So what is your question exactly?

Thread Starter


Joined Oct 10, 2014
Given the swap from the 4000 series to the DG5xx one, I was wondering what could've been the merits of the latter. So, basically, it all boils down to the speed of the latter making it more viable with high-speed ICs. right?


Joined May 19, 2014
Lets fix some terminology first. "4000" refers to a CMOS logic family. The "DG" prefix generally refers to a family of analog switches. There are a few analog switches in the 4000 family such as the 4016, 4066, and 4051. So, I assume that you are asking why are the DG analog switches are better than the 4016, 4051,4066..... analog switches.
The analog switches of today are better in almost every aspect.
- Yup, they are much faster.
- They have much lower "on" resistance.
- They can control much higher frequency signals.
- They have better isolation between channels.
- There many more configurations to choose from.
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