Hi

I am trying to make a circuit for USB to UART. For that I am using:
FTDI230X: http://www.mouser.de/ProductDetail/FTDI/FT230XS-R/?qs=sGAEpiMZZMvVkErl6zY%2bqR%2b6A%2bu/1HB5

WE TVS Diode Array 824011: http://www.mouser.de/ProductDetail/...=sGAEpiMZZMsgNhPy3wz0s7JC25wFgpK3tUoJ3YHBnr0=

Common Mode Chokes / Filters WE: http://www.mouser.de/ProductDetail/...qnvsilMhY5xdooAk%2bM7YdNaABXylUlITcfstZkF/w==

And Ferrite for VBUS: http://www.mouser.de/ProductDetail/Wurth-Electronics/742792641/?qs=5twSNpOB8IBOTWTDxxe6GA==

I have attached the rough schematic.
Am I doing right?
Where should I connect VBUS ( to VCC or VCCIO or 3V3OUT)?
The other pins in FTDI I have marked as NC, Is this OK?
Do I need to add capacitor also in this design?

Thank you all.

 

USB to Serial converter using FTDI FT230X.

 

It looks good but you will need to add bypass capacitors like those shown in the drawing at the page to which ScottWant's link in post #2 takes you. Those components in series with the D+ and D- lines to the chip should not be inductors. If the FTDI datasheet does not explicitly say that damping resistors are not needed on the D+ and D- lines you should put them in series of the lines where what looks like inductors are drawn.

 

Have a look at these. Very good way to protect your PC is to isolate the output of your serial driver.
http://www.mornsun-power.com/html/product/Transceiver-Module.html
This one probably for your RS232..
http://www.mornsun-power.com/html/product/RS-232-Transceiver-Module.html
They do RS485 and CAN too.

 

Both of your links end up at the company's front page for some reason.

http://m.mornsun-power.com

What are the numbers of the parts to which you refer?

 

The links work for me, but if you move the mouse, it changes. I don't like that sort of web site.
Here is one part..
TDx01D232H http://www.mornsun-power.com/uploads/pdf/TDx01D232H.pdf
And a dual one...
http://www.mornsun-power.com/uploads/pdf/TDx02D232H.pdf

RS485... http://www.mornsun-power.com/uploads/pdf/TDx01D485.pdf low speed
http://www.mornsun-power.com/uploads/pdf/TDHx01D485H.pdf high speed
http://www.mornsun-power.com/uploads/pdf/TD5(3)21D485H-A.pdf Auto switching.

There are quite a few more too.

 

The links to the pdf files all work. Those are pretty nice looking modules! I didn't realise that you could buy them ready-made.

 

Yes, they are pretty neat. And not overly expensive!

 

Thnaks. The module looks good.
But I have made some progress with my design.
The previous doubt were very well clarified. Thankyou DickCappels

I want to protect TXD and RXD. Can I used the same circuit as I used for D+ and D-?
Do I need to use LC filter for TXD and RXD or only TVS diode will suffice?