low output impedance MUX

[mook johnson]

I have a requirement to drive 32, 5 volt devices, with a 10mA current draw
each. I'd like to power each one on, one at a time, and cycle through
several times per second.

Does anyone know of a 1:8 or 1:16 mux (or device with similar functionality)
that has an output impedance lower than 10 ohms?

 

[Rich Grise]

"mook johnson" <mook@mook.net> wrote in message
news:W4Sdc.11134$Y45.109@fe2.texas.rr.com...

I have a requirement to drive 32, 5 volt devices, with a 10mA current draw
each. I'd like to power each one on, one at a time, and cycle through
several times per second.

Does anyone know of a 1:8 or 1:16 mux (or device with similar
functionality)
that has an output impedance lower than 10 ohms?

http://www.fairchildsemi.com/ds/74/74AC138.pdf

It's usually not expressed as an impedance, but the spec sheet calls out:

Vol: Maximum LOW Level Output VOltage, at Vcc= 4.5V, max .44V at Iol = 24
mA.

That's for a low side driver - high side is only guaranteed to give you
3.76V
at -24 mA.

There are lots of others, that's just the first one I looked at. You'd need
4 chips, and of course, the counter.

Have Fun!
Rich