All Questions
Tagged with impedance-matching pcb-design
48
questions
0
votes
1
answer
63
views
Understanding impedance matching in RF PCB applications (STM32WB55)
I'm just getting into RF design since I inherited a board that uses an STM32WB55C for BLE. For now I want to start getting more familiar with the RF concepts since I don't have a lot of experience.
As ...
- 871
1
vote
1
answer
47
views
Impedance of different track widths - Should I compute the average width?
Assume that you having one track that goes from 0.11mm in width to 0.09mm in width.
I want to compute the impedance, but I need to select the width. What option should I select?
The largest width of ...
- 1,324
0
votes
0
answers
44
views
Operational amplifier layout- Controlled impedance
In the following picture, we can see a reference layout by Texas instrument for OPA838:
I noticed, in the polygon on the top layer, they have used a specific gap=0.5 mm, I wonder if they used a ...
- 657
1
vote
1
answer
89
views
Layer stack up and impedance matching- 100 ohm
I have a 14 layer stack up as follows (the stack up is from EURO circuit):
I need to provide 100 Ohm differential impedance for my LVDS on layer 7, currently by the information from the manufacturer (...
- 657
3
votes
1
answer
99
views
Which antenna trace design is better?
I need to design an antenna trace (WiFi and Bluetooth) that connects an ESP32-S3 chip to an IPEX connector with an impedance matching circuit.
I have some constraints that I need to work around:
...
- 169
0
votes
1
answer
60
views
Ultrasound System Design: Navigating Transmission Line Challenges and Impedance Matching
Hello community!
I'm currently working on the design of an ultrasound scanning system, and I'm seeking guidance, particularly in the realm of high frequency PCB design and transmission lines.
My ...
- 173
1
vote
1
answer
122
views
Routing traces underneath impedence controlled traces in 4 layer PCB
I am working on 4-layer PCB with following stack-up:
Layer-1 Signal traces
Layer-2 Ground
Layer-3 Ground
Layer-4 Signal + Power traces
The PCB contains ESP32-S2 MCU with USB and chip antenna. I ...
- 45
2
votes
2
answers
241
views
Impedance matching from PCB to cable
I am designing a PCB board connecting to a 2 meter long cable with 75 Ω impedance. I have an output buffer amplifier at the output of the PCB.
For the buffer op amp with 0 output impedance, should I ...
- 33
3
votes
1
answer
272
views
Why does a 4 layer PCB board significantly reduce the trace Width needed for a 50 ohm transmission line when compared to a 2 layer PCB board?
I am designing my first 50 ohm impedance trace on a PCB that connects to a single wire antenna. I was playing around with JLCPCB's impedance calculator and I noticed a significant reduction in the ...
- 1,072
4
votes
3
answers
649
views
PCB design for high-frequency differential lanes (PCIe and USB)
I have designed an M2 adapter which converts from KeyE to KeyM.
Practically this means my board can be inserted into a KeyE slot, and it can host a KeyM SSD.
Gray rectangle is the KeyM socket on my ...
- 969
4
votes
1
answer
167
views
Impedance considerations
I'm desiging a PCB which uses USB (2.0) and PCIe (2.1).
USB is not that fast, however it's said its impedance might have to be correctly set to around 90Ohm +/- 15%.
Now on the other hand, PCIe's ...
- 969
2
votes
0
answers
66
views
HDMI: What is the maximum acceptable differential impedance variation and for which length
Imagine I have a HDMI bus with differential impedance 100 Ohm and length 10cm
Imagine that for a segment of length "L" there is an impedance variation of "DELTA"
Question: in order ...
- 21
0
votes
0
answers
203
views
Via for 50 Ohm impedence track to U.FL connector
There's a 4G LTE modem along with GNSS capability mounted on the bottom layer of a 4 layer PCB. Its a 4 layer PCB with JLC04161H-7628 Stackup. 50 Ohm impedance trace needs to go to U.FL connectors on ...
- 597
1
vote
1
answer
93
views
Matching network for a resistive matched source, line and load?
Suppose we have a well designed 50ohm antenna and source (as there are in many RFIC, and antennas), and we design/use a noticeable long 50 ohm trace/cable in between. If I recall right, this design ...
- 161
0
votes
1
answer
212
views
1Gbps serial bus length matching
How tightly should trace lengths be matched for a 1Gbps serial databus? It seems to me that 100ps (15mm) should be more than sufficient. However:
The Raspberry Pi Computer Module 4 (CM4) datasheet ...
- 533