More symbols - FA2012, RT9711 and DTC123

Álvaro Lopes alvieboy at alvie.com
Tue May 26 10:05:56 CEST 2009


Werner Almesberger wrote:
> Wow, you keep on making them faster than I can review them ;-))

We're almost there, you can rest later :P

>> FA2012: 4x low-pass filter
> 
> The symbol looks good, but we should use the vendor's pin numbering.
> The pin numbering Openmoko used is strange and may be based on a
> footprint we'll have to redo anyway.

Updated. Also changed the pin names to IN/OUT as in datasheet.

>> DTC123: Digital transistor (with internal resistors)
> 
> Looks good, except that the bottom of the box was extremely close
> to the internal connection. I moved it by 50 mil.

I though about that too, but left it as-is because both datasheet and openmoko symbols also had it very close.

> However, this transistor may have other problems. The Rohm data
> sheet suggests an unconventional pin numbering:
> http://www.rohm.com/products/databook/tr/pdf/dtc123je.pdf
> 
> Other sources, namely NXP
> http://www.nxp.com/acrobat_download/datasheets/PDTC123J_SERIES_5.pdf
> and ON Semi
> http://www.onsemi.com/pub_link/Collateral/DTC114EET1-D.PDF
> all use "normal" pin numbering. So I'm almost certain that Rohm
> flipped the chip on its back and chose not to mention it.
> 
> We can verify this by checking what happens in an existing
> GTA02. If my suspicion is correct, pins 1 and 2 need to be swapped.

If they differ, we should rename it to "dtc123_ebc" maybe (emmiter 1, base 2, collector 3).

> By the way, I still have the three logic 1G and 2G logic components
> to merge. Nobody complained about a 74X1G123 naming convention so
> far, so I guess I'll just rename and add them.

Yes, I like that naming convention.

Álvaro




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