3
votes
Inductor sign with single line on the top
FB means ferrite bead.
In the first circuit the beads are not used and 0R resistors are used instead.
In the second circuit, these are used.
There is no mention what parameters (impedance, current ...
- 138k
2
votes
Accepted
Should two different DC power supply GNDs be connected to each other on a PCB?
You would usually connect all the supplies on a single board together back to one GND. Some would suggest you seperate digital and analog grounds in sensitive systems but I don't think this applies ...
- 2,090
2
votes
Automatic serial number on a PCB
It depends on what you ask the manufacturer to do!
You might just submit your single board with the info "10 pieces of this" to your manufacturer. The manufacturer takes your design, and ...
- 90.9k
2
votes
How to read schematic for PCBs
How do I learn to read a schematic and understand the function and how the circuit work?
Practice and experience. Read books, take lectures and watch YouTube videos. Like people, every circuit is ...
- 648
1
vote
Pull up or pull down resistor for potentially unused inverter input?
From the data sheet, the magnitude of the input high current is much less than the input low current. So pull-up resistors are my choice.
LSTTL has an input capacitance of about 5pF. So to realize ...
- 13.6k
1
vote
Pull up or pull down resistor for potentially unused inverter input?
Generally, for LS TTL, a pull up makes slightly more sense. Usually that is because before LS TTL ICs, there were other TTL ICs and those consumed much less current with a signal that mostly idles ...
- 138k
1
vote
Should two different DC power supply GNDs be connected to each other on a PCB?
Yes the H bridge IC references signal inputs and motor drive to same ground pin, so you must connect the 5V and 12V grounds tohether.
If you connect only the 5V of the 5V supply but not the 0V of the ...
- 138k
1
vote
Accepted
Earth for custom POE+ board design
That's not "Earth" literally, but it could be. It depends on your exact scenario, but if your RJ45 socket has a metal shell, it connects to that, as it might be Earth if you are using an STP ...
- 138k
1
vote
Which stackup to choose for JLPCB FR4 up to ~10GHz
It really depends on the material of the PCB. If you just went with Isola FR408 YMMV because the dielectric constant might vary from your calculations of the design
Here is an example that a user ...
- 78.1k
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