Add AD831

[zoonman]

Adding AD831 mixer from Analog Devices

Official page https://www.analog.com/en/products/ad831.html
Datasheet https://www.analog.com/media/en/technical-documentation/data-sheets/AD831.pdf

Symbol Screenshot:

The datasheet one:

I reused existing footprint because there is generic one that matches described in the datasheet.

[CLAassistant]

All committers have signed the CLA.

[myfreescalewebpage]

@zoonman thanks for this contribution.
In KiCad, pins should be grouped by function, i.e. GND at the bottom, power at the top, etc, not by the physical position of thep ins.
Please review.
Thanks,
Joel

[evanshultz]

In addition, the description is dramatically verbose.

[zoonman]

Thank you, guys. I was reading the contribution guidelines and found it pretty confusing. Please, don't mind, I am not electronics engineer. I will try to improve this PR.

[zoonman]

@myfreescalewebpage @evanshultz I made updates to description and pins layout.

Here is updated screenshot:

[myfreescalewebpage]

Hi @zoonman , thanks for contributing,

A few comments I have during my review:

• AD831 does not exist and APZ is the ROHS version, only "AD831AP"' is expcted, please remove the others
• The description should end with ", PLCC-20", no dot, I suggest Doubly Balanced monolithic Mixer, 500 MHz BW, +24 dBm, IP3, LNA and LO driver, PLCC-20
• No comma required in the keywords
• Symbol is not centered (see travis log)
• Pin offset should be 20mil (see travis log)
• Pin length should be 100mil
• Name of pins 1, 9 and 12 is "VP", name of pin 2 is IFN, etc etc. You should use the exact names from the datasheet to avoid confusion
• Pin 14 (BIAS) should not be at the top of the symbol. I suggest in the bottom right corner just below IFN
• IFN and IFP should be Open Collector
• VN pins should be stacked
• GND pins should be stacked
• Probably grouping AP/AN with IFP/IFN is betetr to simplify wiring in the schematics

Will do a complete review after these points are corrected.

Cheers,
Joel

[zoonman]

@myfreescalewebpage I think I got everything cleaned up. No complaints from Travis.
The only one thing bothers me is the stacked pins. I hope I did this correctly.

[myfreescalewebpage]

@zoonman thanks for all the fixes!

• One comment remain: we do not add ROHS versions in KiCad, please remove APZ version
• VP should not be stacked, only GND should be stacked
• VN should not be stacked (sorry it's a mistake in the previous comment)
• One point forgotten previously: footprint filter should not contain the number of pins, it should be PLCC* only for this symbol
• Looking at the datasheet I propose you the following modification of the design to simplify the wiring, let me known:

Joel

[zoonman]

@myfreescalewebpage, I followed your instructions and got it updated:

I hope this is final version.

[myfreescalewebpage]

Perfect, thanks. No more comment to do, merging.
Joel