I'm curious how much current it is safe to pass through a 0.1" pitch pin header. I'm sure it will depend on the gauge and stranding of the wire attached to it as well, but assuming that is not the limiting factor how much could be safely passed?
Electronic – How much current can a 0.1″ pitch pin header pass
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Related Solutions
For a similar requirement, converting a 20-pin header strip to screw terminals, we fabricated a tiny adapter PCB with screw terminals like this one:
The screw terminals are on 0.197" centers, and they interlock nicely on a 0.2" pattern.
The PCB used was thus:
The screw terminals are arranged in two rows atop the PCB on opposite sides of the header strip, facing outward for ease of connecting wires. The 0.1" header strip is on the underside of the PCB, facing the board to be connected to - Either make or female header strips are soldered in, depending on requirements.
You could as well fabricate this using single-sided stripboard or veroboard, just that the header strip on the underside would then need to be soldered with a bit of finesse.
Another such adapter board of ours uses the screw terminals all on one side of the header strip, with a bit of a gap between the 2 rows of screw terminals. That version's a bit fidgety to use though.
Absolute maximum ratings are there to tell you what is (pretty much) guaranteed to damage your IC if exceeded, they are not recommended for normal use (notice the "at these or above..." in the first clip below)
All decent datasheets will have recommended operating conditions, which are the ones you want to go from rather than the absolute maximum values. For most small micros, 15-20mA is a typical maximum operating condition.
In the datasheet for your uC, it gives a table showing the OH and OL voltages over current, which both range up to 20mA. Note the voltage rise/drop at 20mA and you can see exceeding this will cause the OH and OL levels to go out of spec compatibility wise (example shown for 5V supply - things are different for 3.3V and 1.8V)
For example you can see at 25°C, the output low voltage is at around 0.5V @ 20mA (more with higher temp)
So, I would assume 20mA max for the outputs (at 5V - see other tables for 3.3V and 1.8V). Also take note of the little notes under the tables detailing the guaranteed hi/lo input values and combined current ratings.
Basically decide on your operating conditions (temp, voltage etc) read all the tables carefully and do the math to make sure you keep within specs.
If you are planning on driving some LED displays, either use an appropriately rated driver chip or add some discrete transistors on each pin to drive the LED. Unless you are only using a couple of low current indicator LEDs, this is generally the way to go.
Best Answer
Samtecs TSW standard 0.1" header has a variable voltage and current rating based on the matching connector it plugs into. This is due to how much surface area makes contact with the header. That says, it averages 4 to 6 amps per pin.
http://suddendocs.samtec.com/catalog_english/tsw_th.pdf
Based on the common design and material, most headers will have similar properties.
When used for stacking, as in two boards soldered to the same header, the max amperage is 3 amps @ 80 degrees C (I'm assuming per pin). Except for some of their dedicated power strips which have 8+ amp.