working on a pcb which incorporates wo stepper motor drivers I integrated a reverse current diode array to protect the drivers.
First shot was to have 2x8 single Schottky diodes on the pcb. To ease soldering etc. I came across with a special Schottky diode array from Texas Instruments (= UC3610).
Now my challenge is to create a schematic symbol plus a footprint for this device. But I have no idea how to design a symbol which represents 1:1 the diode array on the schematics of the pcb and the corresponding footprint. Issue: the diodes come already internally pre-connected, so I can’t break it up like a 7400 or other “internally independent components” of a package.
For a better understanding see the attached schematics of the UC3610 diode array.
My today’s workaround is, to have the symbol designed just as a “black box” with labelled pins which then can be used in the footprint adequately.
So - does somebody have an idea how to have a detailled schematics including the diode array and the corresponding footprint?
I see no problem to split this network to one component with 8 parts. Select “Edit pins per part” and go on… uc3610.zip (617 Bytes)
Of course you have to be more careful when choosing particular parts during capturing your schematic.
EDIT: Sorry, I forgot to check very important option for this component: All units are not interchangeable. Check this option if you plan to use automatic annotation tool!
Here you go (especially in the audio IC environment, there are dozens of these integrated circuits); I suppose that in these cases you can only use “dummy” circuits which only handle the externally available pins, can’t you?
Well. I see neither the reason nor possibility to split this kind of circuit to the three separate parts. They are not independent.
IMO this is the better example: http://www.datasheetlib.com/datasheet/645189/ul1102_unitra-cemi.html
Six transistors in two bare differential amplifier circuits. We can not split this for the 6 transistors, but we can create two complete parts with 3 transistors per each.
In case of UC3610, we had a better situation. This diode network can be treated as 8 separate diodes, but to make it more legible, the network should be treated as 4 protection units (clamping diodes).
I won’t argue what is the better example and what not.
Both examples are alike having internal connections with no external pins available. So I think the best workaround is to just look at the outside of the pins and create the adequate symbol/footprint.
On the overall schematics side one should then reference to the internal circuit of the component(s). Imho a screenshot of the datasheet circuit and attached as picture to the schematics will do.
I agree. Being a semi-pro / hobbyist for me it’s helpful to have all the information of a project in one place.
So what I will do is, following your suggestion, not to care about the “internals” too much, but attach the adequate data sheet(s) to the schematics to have everything in one place.
