More symbols - FA2012, RT9711 and DTC123

Werner Almesberger werner at openmoko.org
Tue May 26 01:37:01 CEST 2009


?lvaro Lopes wrote:
> Three more components for you to review (in svn):

Wow, you keep on making them faster than I can review them ;-))

> 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.

> RT9711: Power switch

Perfect.

> 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.

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.

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.

Thanks a lot !

- Werner



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