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Shared or separate SPI buses for peripherals in a PCB?

1234 1 Apr 11.2019, 10:57:23

I have four SPI-controlled chips which I want to control from Zynq-7020 via an FMC LPC connector. Each chip/device requires an SCLK, MISO, MOSI and CS line.I'd like to give each device their own separate SPI bus, but for my given application, I don't have enough clock capable (CC) pins on the FMC LPC connector to give each device their own SPI SCLK. I do have enough pins to give each device separate MISO, MOSI and CS lines. There are a few options on what I could do, and I am wondering what the advantages/disadvantages of each would be:1) Every device shares a single SPI bus (Separate CS lines, but shared SCLK, MISO, MOSI)2) Shared SCLK, but separate MISO, MOSI, and CS lines for each device3) Separate SPI buses, driving SCLKs through LA pins instead of CC pins on the FMC LPC interface. (I am not sure if my FPGA would like that I am driving a clock from a non-CC pin)My target device is a PCB, what implications would each of the three options have on my design, and what would be the best...

Isolating main power traces on backside of the PCB

1262 1 Mar 20.2019, 09:37:52

I am currently making a build-in PSU for my own audio-effect-rack-thing. The internal PSU consists of two print-transformers(THT), one for 6VAC and the second one for 9VAC. These are also pretty low power ones (max 1A on the output). I want to put the PSU circuit on a perfboard, since this is a simple design. I am already familiar, that there needs to be a decent airgap between main-rails on the PCB. Therefore, I can remove all the unconnected dots, so there can't be a spark. Now my concern is, when I put the psu circuit in the case, that the backside of the PCB (and therefore the mains(230V) power traces) are touching the case internally. How can I safely prevent this from happening and is there a better way around ?My thoughts:painting the backside with somethingputting a plastic sheet beneath it

What program do you suggest for making the PCB Gerber file?

1221 1 Mar 19.2019, 10:14:17

I am trying to make a PCB Gerber file. Do you have any good suggestions?

How can you solder surface-mount technology on a PCB without special tools?

1158 1 Mar 18.2019, 10:19:38

How to Solder SMD / SMT Components With a Soldering Iron?

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