Questions tagged [guard]
6 questions
13
votes
4 answers
Implementing guard trace/ring in PCB design
I have read here and there some articles about pcb guard trace/ring. But none of them discussed how to correctly implent it. What I could find were some pictures and comparison that cant help me at the moment!
What I would like to know is how can I…
Dumbo
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10
votes
4 answers
Active guard shielding for instrumentation amplifier
I want to use the the AD8221 amplifier as a conditioner for my load cell. I saw that to reduce noise I can use an "active guard shield driver" between the "REF" of my amplifier and the shield.
If someone has already worked with something similar…
user278935
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- 4
6
votes
3 answers
Opamp Guard Polygon: Only in Top PCB layer or or all layers
I have an opamp circuit as shown below.
My board stack up is SIGNAL-GND-POWER-SIGNAL.
I am providing a polygon to Guard the trace which is going to non-inverting
the input of the opamp.
The guard trace is connected to SMA connector also. At present…
Hari
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5
votes
1 answer
Considerations for PCB guard ring trace for PH probe
Long time lurker first time poster. I have questions regarding PCB guard rings in a pH meter circuit. I know that a typical combination pH electrode has really high output impedance so you want low leakage on the PCB as well as low input offset…
Andy
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- 3
2
votes
1 answer
How to fix oscillations in cable guard drive?
I am designing a guard drive for a coaxial cable, to drive its shield as a guard for low leakage measurements. After seeing some issues in the sim, I arrived at the following minimum circuit which reproduces the issue:
The lines from right to left…
tobalt
- 18,646
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1
vote
0 answers
Designing a guard ring for a transimpedance amplifier
I am at that stage of a PCB design where I need some guidance on guard rings.
The Application:
The application is a photodiode circuitry (using a pin photodiode and transimpedance amplifier.) The amplifier output polarity is (-)ve. This is then…
LabMat
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