New answers tagged

1 vote

GNU radio FRS transceiver

Your antenna requires a ground plane to be effective. It's a magnetic mount (magmount) antenna, that is to be placed on a metallic plate having a minimum diameter of 300 mm (the larger the better). ...
user avatar
  • 11.1k
3 votes
Accepted

500 mV p-p noise in two stage photodiode amplifier output

I would start by looking in this direction: - Your power supply noise is less than 3 decades above your power supply filter cut-off point i.e. 160 Hz --> 1.6 kHz --> 16 kHz --> 160 kHz. This ...
user avatar
  • 389k
1 vote

How to mitigate noise from DC-DC converter used for reverse biasing diode?

Your scope might be picking up inductive pulses from the regulator, especially in its ground lead. Try moving your probe away from the regulator, even to the opposite side of the board. You can ...
user avatar
  • 40.9k
1 vote

Why does touching LEDs' ground terminal light them dimly?

Case 1: The LEDs don't light up since the applied DC voltage, for three of them in series, is as low as or even lower than the forward voltage of one of them. Case 2: The LEDs light up dimly on ...
user avatar
  • 11.1k
1 vote

Why does touching LEDs' ground terminal light them dimly?

First of all, 3 leds connected in series adds up to about 9.9 volts. Three volt power supply would work if leds are connected in parallel, if the supply carries enouph current. The leds lighting up ...
user avatar
-1 votes

Why am I getting such widely ranging values from this TMP36 in this circuit?

https://github.com/Joe0x7F/TMP36 The TMP36 is a terribly unstable device. Try a MCP9701A or a LMT87.
user avatar
1 vote

ESP32 restarting when relay is turned on

I think it is unlikely that you are actually getting those high voltage transients on the 3.3 V logic rail, or you would be seeing damage to those components. More likely the transients form the AC ...
user avatar
1 vote

ESP32 restarting when relay is turned on

You can check the reset reason of the ESP32 through esp_reset_reason() If it's "brownout detector" you know the spikes are the cause and you need better ...
user avatar
  • 205
0 votes

How to eliminate the noise of this circuit?

EMG is easiest done with active electrodes, with effective electrode wire lengths approximately zero. The signal amplitude is lower than EKG's - in fact, EKG is a cumbersome common-mode artifact in ...
user avatar
0 votes

How to find noise sources from noise figure data?

I think that the frequency is not necessary here. It might indicate that we are dealing with noise above the 1/f flicker noise regime. Accordingly, the white noise (thermal noise), can be described ...
user avatar
  • 395
2 votes
Accepted

What is the dimension of Attenuation in the LC-EMI filter design formula?

The computed attenuation \$Att_{LC}\$ is probably in linear units. That is, the input signal is 1878 times the output signal, or a gain of 0.532m. I much prefer working in gain rather than attenuation,...
user avatar
  • 144k
3 votes
Accepted

DM and CM EMI emissions measurement in LTspice

Both of the terms for CM and DM noise need to be divided by two. In the picture below you can see how CM and DM currents are flowing and how they can be separated. Source: AnalogDialogue article
user avatar
  • 1,653
1 vote

Reduce noise on 2m I2C bus using motorcycle power

As suggested by others, the right way to do it would be to choose a more robust protocol and shielded cables. However, if for any reason you have to use the I2C protocol and the shielding is not ...
user avatar
  • 326
4 votes
Accepted

How to have a wider spectrum of FFT at LTspice?

If you're doing an AC analysis in LT spice then you need to change the max sweep frequency in the .AC statement. If you're doing a .trans analysis and converting it with the fft later then you need to ...
user avatar
  • 64.4k
1 vote
Accepted

How to calculate RMS noise from datasheet?

EE&O ... How to calculate RMS noise from datasheet? S/N ratio is just defined for 1 frequency \$Fmclk=25 MHz\$ and \$Fout=Fmclk/4096\$. But I would not consider it is a "normal" s/n ...
user avatar
  • 6,031
1 vote
Accepted

Mixer noise calculation

A mixer doesn't necessarily generate noise. However, there are several ways in which in it can degrade the noise of a system. Via signal attenuation. If the mixer drops the signal level 6 or 7 dB, ...
user avatar
  • 144k
2 votes

Introduction of noise when ADC is active

You add DC offsets to the OpAmps IN+ path via these resistors: R9, R11, R21, R34. The voltage source of this offset is the noisy 3.3V, attenuated around 100:1 and amplified again a little below 1:50. ...
user avatar
  • 3,442
3 votes

Introduction of noise when ADC is active

As pointed out in the datasheet ... VA is used also as the reference for the ADC ... Positive analog supply pin. This voltage is also used as the reference voltage. This pin should be to VA Supply ...
user avatar
  • 6,031

Top 50 recent answers are included