I downloaded the official PSoC 4200 PCB footprint libraries for Allegro, Altium, and Pads and there does not seem to be an official footprint for the WLCSP 35-ball package (the FN package). I have the 4200 family datasheet (001-87197 Rev. *J), and there is a drawing of the package on page 38, but no corresponding footprint specification. I have read JEDEC Design Guide 4.18 per the instructions in the datasheet, but it (as expected) only describes the package, not the recommended PCB footprint. I, of course, have the die WLCSP package size and pad spacing from the datasheet, so that's not an issue. All I need is the recommended pad size to complete the footprint myself. Any suggestions?

Edit: I found an application note from Freescale (now NXP), AN3846: Wafer Level Chip Scale Package (WLCSP), from 2012 that provides guidance for their WLCSP packages for both PCB layout and manufacturing. There is a copy here:

https://www.mouser.com/pdfdocs/AN3846.PDF

They say their their solder balls are 0.250mm in diameter, but Cypress says theirs are 0.260mm. I am going to guess that if I scaled the pad sizes by 0.260mm/0.250mm = 1.04, that I would get the right pad sizes for the process specified by Freescale/NXP. It's a bit of a bummer that Cypress doesn't seem to have any guidance at all on this even though they provide WLCSP packaged chips.

Hi ,

I am using CY8C4128LQI-BL543 trying to measure the ECO frequency with a frequency counter. I am using the reference guide for it. unfortunately, there is not reference to how to route the ECO to the GPIO for measurement, although it is mentioned in the reference document that it is needed as part of the Xtal trimming

the reference document is here:

https://www.cypress.com/file/139476/download

and the reference for routing is here:

Hello, I require a Bilateral switch as per a 4066, I have tried using the creation wizard, but limited editing of the functions prevents me from creating this component, is it possible, or is there an example in existence already?

Kind Regards 

Hi ,

For an application without having the ability to pair with the device (since we are using one Master phone to scan multiple peripheral sensors), we would like to use application level encryption. I know that encryption and decryption using SW is very long , therefore usually using HW block for that. Is there any way which I can use the encryption/Decryption HW block directly ?

Couldn't find any reference for it online.

Hello, I need experts assistance for Pcap button layout.

Because of the limited board area, we plan to use 4-layer board for a 8 buttons, 5 LEDs and 2 connectors (have other PWM signal,  LED signals......). see attached mechanical drawing.

Follow AN64846 <Getting Started with CapSense>, the top layer is CapSense; layer2 is CapSense traces; layer3 is hatching Ground; bottom layer is other components and traces.

Our mechanical design has 2 connectors exactly underneath 3 buttons. According to <Getting Started with CapSense>, it says:

.........

* Isolate switching signals, such as PWM, I2C communication lines, and LEDs, from the sensor and the sensor PCB traces. Do this by placing them at least 4 mm apart and fill a hatched ground between CapSense traces and nonCapSense traces to avoid crosstalk.

* Avoid connectors between the sensor and the controller pins because connectors increase CP and decrease noise immunity.

.......

With a hatching Ground plane layer3, Can the connector directly under the button? And should all other traces (on bottom layer) at least 4mm apart from CapSense (on top layer) and CapSense traces (on layer2)? 

Thanks.

Chang Cao

Dear all:

     We use 4024 as a multi-Capacitive touch key processor. It generate an interrupt signal when touch down event be detected.Now we need check response time of our mass product.Can you tell me how to test ?

     There is a planstic cover on the touch key sensor which was connect to PCB by FPC.

Thanks!

Li Min

Hi,

I have opened the Temperature sensing project for CY8CKIT-147, but I have received the error on ADC_SCAN (Old version block), What can I do ?

See the attached file.

Hi everyone,

I am currently facing a problem on making fft works using CMSIS DSP library. Basically, I want to convert real time data from my sensor into frequency data by using FFT CMSIS DSP library. However, it only works for the first loop. I debug the code and somehow the program is still running after the first loop but i cannot find the location of the code where the program is running after first loop (Step Over). Does the FFT messed up the memory location of every function in the program or i cannot call the FFT function more than one time? Thank you.