Tagged Questions

4
votes
2answers
106 views

Returning Currents for two side boards and returning current questions

I have some questions these are I am not sure: I have designed a board that has classical 2 side PCB design. Frequency is not a big issue for me but with ESD my CPU resets itself. (CPU clock 20 Mhz, ...
10
votes
2answers
774 views

Why are vias placed this way on a PCB?

I used to check complex commercial PCBs specially those of graphics cards to see how professional PCB designers do their layout and learn from their techniques. When I checked the card shown below I ...
2
votes
2answers
252 views

Signal integrity at 40 MHz with parallel signals

I have to design a board with an 8 bit parallel port that carries 40 MHz signals. It is not possible to wire them very short and in parallel (I am sure the wires will be about 7 cm long), so I have to ...
4
votes
2answers
277 views

Routing considerations of analog signals on twisted pairs

I'm designing a part of a system that will receive 4 analog signals carried on 4 twisted pair cables which are input to an ADC. These signals are low speed (probably in KHz) bipolar ranging from -10V ...
2
votes
2answers
352 views

How can I meet these PCB design conductivity/isolation requirements?

The specifications required are as follows: The resistance between ground pins on a connector and the case (chassis) ground should be less than 3 Ohms. The resistance between any other signal on the ...
2
votes
4answers
354 views

What's the Actual Speed in GHz of RapidIO or RocketIO serial interfaces?

When reading about high speed serial interfaces like RapidIO or RocketIO, I find data rates of 3.125 Gigabits/second and more. My question is: 3.125 Gb/s = ?? GHz What's the relation between Data ...
10
votes
2answers
658 views

How to transmit high current (2.6A) with low voltage (1.2V) for a long distance?

I want to supply a DSP with 1.2V. This DSP needs 2.6 Amps of current at full load. The minimum supply based on the electrical specs of this DSP is 1.16V, which means that the maximum voltage drop ...
6
votes
3answers
643 views

Want my PCB design to work right the first time!

Just finished a design of a 8-Layer PCB, the highest frequency is 125MHz. I want this design to work right the first time, how should I revise the design and what should I take care of? Something ...
3
votes
3answers
411 views

Best way to learn Signal Integrity

I am currently working on ECAD. Just to add more technical values to my work, I want to learn Signal Integrity and Thermal Analysis. What are the books,links you would suggest me to learn it? I am ...
1
vote
2answers
758 views

PCB and trace design for high-speed TTL

I am designing high-speed TTL-based processor. I will be using only fast AC, ACT and LVC series, so switching frequencies will be in 100Mhz range with 1-3ns fronts. I plan to use homemade 2-sided ...
7
votes
2answers
919 views

PCB routing: EMI and signal integrity, return current questions

If there's any EMI/SI lesson I've taken in, it's to minimize return loops as much as possible. You can work lots of EMI/SI guidelines from that one simple statement. However, not having or ever even ...