As always - masses of information missing from the question. Sorry, but I get a bit tired of this and wish people would just take note of how other questions have come off the rails by omitting basic relevant information before plunging in and asking their own. Anyway, grumble over...
What voltage ranges are you talking about (0-5V, 0-20kV,...) , what current ranges are you taking about ( 0-10 uA, 0-100 A,...) , DC or AC, if AC what bandwidth?
A 4066 will be fine for medium speed digital signals or lowish level analogue signals (0-5V, possibly higher depending on supply voltages, a few mA) but bugger all use if you want to drive a one horsepower AC mains motor from it.
Relay, TRIAC, opto-isolator, transistor, mosfet, SSR, and some/lots of multiplexers, CD4066, adg333, max333, adg201/202, ULN2003/2803, TPIC6B595(and the A and C variants), and many more things might be able to achieve what you want.
But, voltage, current, isolated or not, needs to be known..
hoo sorry but I forgot describe the main functionality to this circuit. As I said I intend through MCU switch on or off a contact where this contact actuate a various loads, like leds, LCD 16*2 (signal and power), keyboard matrix.
Therefore the values of loads will prowl 0-5VDC and maybe 200mA maximum.
I am reading the datasheet and I highlight these points:
1-SWITCH ON RESISTANCE MATCHED TO WITHIN 5Ω TYPE. OVER 15V SIGNAL INPUT RANGE - (these means which the resistance represent ever 0.33% of voltage? E.G. to 5VDC I will 16mΩ?
No, it refers to what it says, the
matching of the on resistance (R
on) of one switch in the IC package to the on resistance of the other switches in the package, how close in value they will be. I have no idea what you think is going on with "0.33% of voltage? E.G. to 5VDC I will 16mΩ" but it suggests to me that you have either some serious misunderstanding of the very basics (i.e. Ohm's law) or great difficulty in expressing yourself (I take that you're not a native English speaker, even though you appear to be resident there).
2-EXTREMELY HIGH CONTROL INPUT IMPEDANCE (control circuit isolated from signal circuit 10^12 Ω typ.) - (these points it is good, right? Because this means that the circuit will offer a higher resistance on input pins "IN/OUT", right?
Erm, yes, sort of. It's alluding to the loading effect of the inputs on the input signals (i.e. from the MCU). With CMOS microprocessors the input
capacitance is usually the parameter that one would worry about and which has a much greater effect on loading that the input resistance of a CMOS gate which is typically very high. I doubt it is anything you need to worry about too much at the moment, but it wouldn't hurt for you to research the concept of "fan out" for digital circuitry.
3-QUIESCENT CURRENT SPECIF. UP TO 20V - (what means this point?);
Just that, that the quiescent current for the chip is
specified for all supply voltages up to 20V, that is, it is not
unspecified at any point. Don't worry about it - presumably some datasheet(s) for this part from some other manufacturer(s) left I
q unspecified under some conditions and the marketing department at SGSThompson decided it was worth pointing out that they had fully characterised the chip. That block of bullet points at the start of almost every datasheet is nearly always just marketing BS and should be ignored in favour of whatever the rest of the datasheet actually says.
The R
on of the
x4066 type of analog switch is pretty high. You can see from the datasheet that with a 5V supply it has the potential to be as high as 1k ohm. That's fine for a high impedance signal line, but if you're pushing any current worth mentioning it will be a problem (e.g. at 1mA you'll see a whole 1V drop across it). This chip isn't really designed for switching anything more than low level signal lines. If you're looking at 100mA then you're probably in the region where solid state relays are your best bet. In the hinterland between you can probably get what you want with a logic-level MOSFET, but reading between the lines I suspect that you're at the stage where designing with discrete components is going to be problematic for you.
If you're looking at switching
both low level signals
and signals with significant current then you're unlikely to find an economic "one size fits all" solution.
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