Unanswered Questions
26,586 questions with no upvoted or accepted answers
27
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0
answers
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Switch from JTAG to SWD with bitbang sequence on STM32F103VB
I am trying to switch from JTAG to SWD without any external devices. Why? Because I would like to use the SWO pin to send a stream of logging information to
another device.
To accomplish this ...
- 116
10
votes
0
answers
603
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x86 Motherboard Bring Up - Intel Tiger Lake UP3 CPU
For those who has experience with Intel x86 motherboard design and bring up.
I'm in the middle of motherboard bring-up that has Intel Tiger Lake UP3 CPU.
Seems like I had a good run so far at power-up ...
- 1,107
9
votes
0
answers
435
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Estimate base-spreading resistance from Gummel-Poon model
I'm attempting to calculate the base-spreading resistance of BJTs from manufacturer-provided SPICE models, which use the Gummel-Poon model. This Agilent publication (Internet Archive link here, if ...
- 511
8
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answers
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So can we just draw 500 mA from any USB port without enumeration now?
The USB Type-C Spec R2.0 defines the USB Type-C Current feature, in which the power Sink observes the voltage on the CC pin to determine how much current is available from the Source, which falls into ...
8
votes
2
answers
345
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Phase shift near saturation mitigation in input stage amplifier -- How does this work, why does this work?
I'm trying to understand how this circuit works on the input stage to the 4192A Impedance Analyzer.
Apologies for the quality... this is the best scan I could find. The design is furnished with the ...
CommunityBot
- 1
7
votes
0
answers
225
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Extremely long net in Xilinx synthesized design labeled "async_path". What's it for?
I used Vivado to synthesize a small design for the Xilinx xc7k-160t-1. The design includes a fifo instantiated with Vivado's XPM macros which crosses clock domains from 100.8MHz to 200MHz.
When I ...
- 1,439
7
votes
0
answers
295
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Identify kind of cable with markings such as "WE-B 2 PAIR" on the jacket
While cleaning out our back yard shed, I came across a coil of cable of a kind that I have never seen before (image below). It was left here by the previous home owner, who worked in some kind of ...
Null♦
- 7,716
7
votes
0
answers
236
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Frequency locking for averaging resampling
Background
I've done a long one-shot measurement of a periodic signal by an oscilloscope. Thus, I've captured around 250 periods of a signal. The signal itself is a pseudo-random binary sequence at ...
- 711
7
votes
1
answer
2k
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IIP2 Second Order Intercept Rule of Thumb
I'm faced with the problem of explaining the harmonic production in a system where the second order intercept points of the cascaded components are unknown. As a way to bolster my explanation, I would ...
CommunityBot
- 1
6
votes
0
answers
61
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Tapping for monitoring in a safety circuit
I have this machinery piece with a quite long interlock safety line. It's category 1 so it's simply a long series of N/C contacts/limit switches and at the end there's the master safety relay that ...
- 8,896
6
votes
0
answers
915
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Understanding EGSM-900 (LTE 8 band) electromagnetic spectrum
I am trying to fully understand the physical layer of the GSM standard. For doing that I am looking at the E-GSM-900 band (mostly used in Europe). In my country these frequencies has been assigned to ...
- 185
6
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0
answers
1k
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How to protect single cell Ni-MH battery (overcurrent, undervoltage, overtemperature, etc.) during discharge?
Story
I am designing a boost converter for a battery powered board. I am planning to use single Ni-MH battery. The needed output voltage is 3V3. The device will be in deep sleep mode (drawing few ...
6
votes
1
answer
1k
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Ethernet magnetics, discrete vs integrated: inductance value
I recently made a change to an EtherCAT-over-Ethernet design, where I moved from using an RJ45 with integrated magnetics to a low-profile connector with discrete magnetics because of size constraints.
...
CommunityBot
- 1
6
votes
1
answer
6k
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Run IAR Program without Debugging
I'm having a simple problem with IAR Embedded Workbench, programming an STM32 using an ST-LINK/V2 programmer. I'm trying to run a program that temporarily switches off the JTAG pins, so I can't run it ...
- 1,618
6
votes
1
answer
612
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Charge mode piezoelectric signal conditioning
I have a charge-mode piezoelectric dynamic pressure sensor (datasheet link) that I want to read a signal from. If you look at the datasheet it says the sensor outputs are in a balanced and floating ...
