Unanswered Questions
24,256 questions with no upvoted or accepted answers
27
votes
0
answers
3k
views
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
11
votes
0
answers
528
views
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 ...
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10
votes
0
answers
762
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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
1
answer
595
views
What's wrong with my bread maker?
I'm not sure if that's a place I can ask this question. I've got a 10 years old bread maker, that I've used about 50 times.
2 weeks ago, upon turning it on, everything looked and sounded usual (screen ...
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7
votes
0
answers
284
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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 ...
- 1,467
7
votes
0
answers
282
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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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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
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6
votes
0
answers
952
views
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
votes
1
answer
1k
views
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 ...
CommunityBot
- 1
6
votes
1
answer
6k
views
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 ...
- 1,636
6
votes
1
answer
658
views
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 ...
6
votes
1
answer
1k
views
Is this a reasonable, robust way for detecting voltage crossing a threshold?
Updated, functional design at the bottom of this question
I wish to detect when a low-impedance signal is below or above 60VDC (±3V). When the signal is above 60V, I'd like to indicate this by ...
CommunityBot
- 1
5
votes
3
answers
157
views
Understanding an unusual combination of crossover diodes in a class AB amplifier
Another user had a question about distortion in an audio amplifier. The culprit seemed to be oscillations around Q2-Q4. Here it is again for reference:
Not having a lot of experience with class AB ...
- 87.7k
5
votes
0
answers
182
views
Why does output of this reverse bias noise source not have normal distribution?
I am trying to build a noise source based on reverse biased PN junction (i am trying to replicate this project https://altusmetrum.org/ChaosKey/ ). At this point i tried multiple iterations but so far ...
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5
votes
0
answers
745
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How to match an edge launch SMA connector to a pcb with coplanar waveguide with ground?
I'm trying to develop a pcb that is capable of handling signals over 6GHz and created a test board to see how the pcb and connectors perform. The pcb is a relatively low-cost 4-layer FR-4 TG155 board ...
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