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FurkanDursun , 05-25-2020, 03:38 AM

Hello Everyone,

I work on U-BLOX's ZED-F9P GPS chips.The ZED-F9P is an LGA package with the I/O on the outside edge and central ground pads
I have to design for this chip but I have some questions about this chip.

I would like to ask is this chip requires fanout during the PCB layout design? And Is there any high-speed interface, I want to be sure therefore I looked at the datasheet I didn't see any high-speed interface.

robertferanec , 05-26-2020, 03:17 AM

@FurkanDursun please, could you be more specific with your questions? Looks like ZED F9P is a module, not a chip. Or am I looking at a wrong page? https://www.u-blox.com/en/product/zed-f9p-module

For this kind of modules, you normally only need to connect power and the interface you would like to use (e.g. UART, USB, ...) ... sometimes antenna (if connector is not placed or integrated on the module).

chitransh92 , 05-27-2020, 05:42 AM

Hello,
Fanout is not some technology like HDI or DDR3, it essentially mean that you are bringing your chip level terminal out to connect them to peripherals.
Even though this term is widely used in conjunction with BGA devices, this applies to all ICs.
Its just BGA fanouts are more challenging then fanning out a simple SOIC or QFP device.

So in your design for this module.. You would be fanning out the connection. Yes..
This IC does not have any high speed interfaces... Good for you..

Technically you can..
But if PCB design were just about connecting pins via copper the world would not be able to reach at the magnificent levels of Gbps speeds as it is right now..😊

Place the component elegantly and try to enjoy the whole process..

Thanks.

FurkanDursun , 05-27-2020, 05:40 PM

Thank you very much Mr. Chitransh. May I ask one more question?


I connected several serial resistors with UART(RX, TX ) pins, these resistors will not find out any problem, will it?

robertferanec , 05-28-2020, 06:42 AM

I would not use 1k series resistors .... maybe 22R or 33R. Also, if you are only using these resistors to have access to the signals, you can use 0R or combination of 0R (for input) and 22R (on output) pins (I would go for the last example 0R & 22R). Plus, you may want to place some decoupling capacitors close to the VCC pins (sometimes this is not required as module will have it's own decoupling capacitors, but there is no really harm to place them .... have a look at their development board and reference schematic)

I found their schematic here: https://www.u-blox.com/sites/default...8055649%29.pdf

FurkanDursun , 05-28-2020, 07:34 AM

Thank you for your best feedback Robert. I want to ask one more question about layer stack up. I want to work with 4 Layer (Signal, Gnd, Power, Signal) So, I set some options and also VIAs, here you will see. Are sets True and Useable?

chitransh92 , 05-29-2020, 04:12 AM

Hello,
I would suggest you look up at some fabricators website there are a ton on the web that what 4 layers stack up can be easily manufactured.
They have content on what via type you should for your design and significance of different via types..

Read & Explore!!! ☺
its beautiful out here...

robertferanec , 06-01-2020, 02:01 AM

@FurkanDursun I would suggest to look at some of my videos about how PCB is manufactured, to understand what you can use in your PCBs. For example, ideally you would like to have your PCB stackup symetrical. You need to think about how your PCB would me manufactured - and what is on the picture, that would not really be easy (e.g. what do you think, how they would make the VIAs?) ... they would be probably able to do it, but it would cost you a LOT(!) of money and you can save a lot if you just use something what is much easier to manufacture.

As @chitransh92 suggested, ideally you would like to use a stackup recommended by your PCB manufacturer - I do not know which one you are planning to use, but if one of the cheap chines ones, have a look at their websites. I had a quick look but could not find any recommended stackup with uVIAs / Blind VIAs / Buried VIAs from PCBWay or JLCPCB .. maybe you need to keep searching.

Links:
- How is a multilayer PCB made? https://www.youtube.com/watch?v=67WhV0EDqCA
- PCB Manufacturing - Important facts you should know https://www.youtube.com/watch?v=f6_svRNJYls