1. Home
  2. Electronics Design
  3. charge sources and matrix

charge sources and matrix

Hello,

I have 2 constant current sources available. Now, my application needs

32 current sources or channels. I thought that if I use switching then I can use 2 current sources to get 32 current sources. For example, MAX 306 a multiplexer is also a bidirectional switch which allows to connect one input line to 16 separate independent lines. It has 4 address lines. So, If I use two MAX 306 then I can switch two current sources among 32 channels. So, the two muxes will form a matrix of 16 x 2 (16 rows, 2 columns ). The first column will belong to current source#1 and the second column will belong to current source#2. The problem is that I also do want the current source#1 to access the second column and current source#2 to access the first column...In any scheme I do not want the two current sources outputs to connect witheach other.

Probably, using some switching scheme between these two current sources might solve the problem but in reality I have 32 current sources and I need to convert them into 96.? Please advice!

Thanks John

Reply to
john
Loading thread data ...

Hello John,

First it was 32 channels. Now 96 channels. A bit confusing. Can you post a schematic of what you want to do?

Anyway, my gut feeling is that you need what is called a cross-point switch. Those allow the free routing of x input channels into y output channels. Accidental switching to the same output can be excluded if desired, usually by correct programming. Cross-point switches like current mode drive (less crosstalk).

Regards, Joerg

formatting link

Reply to
Joerg

Hello,

Thanks for ur reply! I meant to say that I have 32 current sources which I need to c> Hello John,

Reply to
john

Reply to
john

Hi,

Thanks for ur reply! I did not understand the "T> "john" schreef in bericht

Reply to
john

"john" schreef in bericht news: snipped-for-privacy@g47g2000cwa.googlegroups.com...

Something tells me it might be easier to make 96 current sources and avoid all that switching.

--
Thanks, Frank.
(remove \'q\' and \'.invalid\' when replying by email)
Reply to
Frank Bemelman

Hello John,

If you can't implement 96 current sources you really need a crosspoint switch here. It's been a while that I used them off-the-shelf in ultrasound beamformer designs because nowadays this gets integrated on ASICs. But on the last one that was COTS we took a switch chip that was meant to be used for ISDN lines. A big fat chip with dozens of inputs and outputs, IIRC it was made by a company that usually does FPGA.

If you can do 96 current sources that could end up much lower in cost.

Regards, Joerg

formatting link

Reply to
Joerg

"john" schreef in bericht news: snipped-for-privacy@z14g2000cwz.googlegroups.com...

I didn't say you *should* not consider switching, I said it *might* be easier to make 96 current sources. If that is not possible, it seems that you need to build your own crosspoint matrix. The available crosspoint switches are intended for video and always have outputbuffers, as far as I know. Building a 32x96 crosspoint matrix from generic analog switches requires a lot of parts, plus a fair amount of digital logic to set the active connections.

And please don't toppost. It upsets the entire newsgroup here.

--
Thanks, Frank.
(remove \'q\' and \'.invalid\' when replying by email)



> Frank Bemelman wrote:
> > "john"  schreef in bericht
> > news:1132672349.789355.10970@g47g2000cwa.googlegroups.com...
> > > Hello,
> > >
> > > Thanks for ur reply! I meant to say that I have 32 current sources
> > > which I need to connect to 96 different locations. any current source
> > > can be capable of acessing any location out of 96 locations and the
> > > current sources\'s output should not be connected together.
> >
> > Something tells me it might be easier to make 96 current sources
> > and avoid all that switching.
> >
> >
> > --
> > Thanks, Frank.
> > (remove \'q\' and \'.invalid\' when replying by email)
>
Reply to
Frank Bemelman

PLONK! (and that is top posting too)

"john" schreef in bericht news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

outputbuffers,

source

the

Reply to
Frank Bemelman

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.