Hi
I need MAX 4564 (SPDT analogue switch) for my graduate project,
But it's not available here at my country.

Any alternative IC you suggest?
Or equivalent circuit that can be made?

It’s difficult here to buy things form other countries.

Please some help.

thanks

__________________
I’m from Syrian Arab Republic where lots of guys are trying to do better in electronics.

 

There are lots of analog switches that might work, depending on your application. Can you describe it, or, better yet, post a schematic?

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Ron

 

The standard CMOS switches are either 4066 parts or 4051/4052/4053 multiplexer parts. The Maxim parts are relatively new switches that have low resistances (40R), support high voltages(12V), and generally have very nice ratings.

Now, you'll have to tell us how much of that capability you actually need, then we'll be able to give you some ideas.

 

The maximum amplitude of the input signal is 100mv + shift voltage about 1.65v

Unipolar supply voltage.

The spdt is to take samples from previous signal.

Two inputs,
one for the input signal and the other for reference voltge about 1.65 v

Attached Thumbnails

 

__________________
I’m from Syrian Arab Republic where lots of guys are trying to do better in electronics.

 

You need to post a readable schematic.

__________________
Ron

 

So the only other bit of information that you're missing is how fast/high bandwidth the signals are. I'll take a wild guess that the signals in this device aren't terribly fast, in which case the using a standard 4051 1-of-8 mux is probably good enough. That said, the 15uF coupling capacitor

So the thing to look for would be logic families. TI has these part
http://focus.ti.com/docs/prod/folder...d74hc4051.html
http://focus.ti.com/docs/prod/folder...74lv4051a.html

The first one is the "standard" HC device which is very common, and the second is one of their LV logic devices that is tuned for low voltage operation.

The other reasons to get a 'better' part are:
1) if you need to switch faster into a lower impedance
2) if you need to make sure there are less parasitic capacitances/charge injection
3) you need more isolation - usually only an issue if you have high speed signals and high accuracy ADC's (12+bits)
4) you need a physically smaller part

 

Sorry for that bad schamatic

In this project we get an ECG signal, so the 1st stage is high CMRR with INA118 amplifire
2nd stage is BPF to get the band 0.1 HZ to 250 HZ
That ECG is shifted by 1.65 DC volt
Then I want to shift the band about 2500 HZ by getting sampels throw the switch that I want....

Attached Files

schematic.zip (57.8 KB, 16 views)

__________________
I’m from Syrian Arab Republic where lots of guys are trying to do better in electronics.