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CH340x: V3 should be power-output

John Beard requested to merge johnbeard/kicad-symbols:ch340x_v3_pins into master

On CH340x ICs, the V3 pin is the output of a 3.3V regulator, which usually needs a decoupling cap to be inserted.

Change the pin type and swap the V3 and VCC pins around to make it easier to connect the VCC pin to the VBUS from a USB connector.

On the CH340X variant, move TNOW/nDTR output to the right side, in the same place as the nDTR for the CH340C.

On the CH340E variant, place the TNOW output also in that position, as this is an output that will probably go to the same place as the serial data (or be NC).

Fixes: #3188 (closed)

E.g. CH340T (and -R) datasheet: https://cdn.sparkfun.com/datasheets/Dev/Arduino/Other/CH340DS1.PDF

The wording isn't very clear but the pin description is:

2023-06-15_231801_818x99_screenshot

This page has a little bit more insight into the pin, and (ab)uses it as a 3.3V input, commoned with VCC): http://cjh.polyplex.org/electronics/3v3_arduino_nano/index.html

New part layouts:

2023-06-15_231504_962x366_screenshot

And in a common arrangement:

2023-06-15_231540_791x559_screenshot

KLC violations:

  • S3.1: CH340T is slightly off centre (odd number of 100mil grids high) - I didn't change this.
  • Remove the instructional content of this template
  • Provide a URL to a datasheet for the symbol(s) you are contributing
  • An example screenshot image is very helpful
  • Ensure that the associated footprints match the official footprint library
  • If there are matching footprint PRs, provide link(s) as appropriate
  • Check the output of the automated check scripts - fix any errors as required
  • Give a reason behind any intentional library convention rule violation.
Edited by John Beard

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