Questions tagged [oscillator]
A device or circuit that generates an AC signal at a certain frequency.
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A 555 timer changes time when you touch it?
I designed a simple 555 astable 50% duty cycle square wave generator, assembled in China on SMT PCB. It works well: Except when you touch it, or even put your fingers near it, the timing changes ...
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Calculate Kv for an OCXO (Tuning Law)
I would like to calculate Kv value for an oscillator with the following datasheet :
https://dl6gl.de/media/files/ocxo-cti-osc5a2b02-datasheet.pdf
I have this formula to calculate it :
Found here ...
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Type 2 comparator locking on ringing
I have successfully designed a 4046 IC with a phase 2 comparator locking to an external 10 MHz VCOCXO. The circuit is simple
vcoxco---->
divide by 10-->
Schmitt Trigger -->
divide by 10 -->...
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Vref out and OCXO
Taken an OCXO and assuming that Vref in should stand for EFC (Electronic Frequency Control) accepting an external reference voltage what is the general purpose of Vref Out in oscillators? And, in ...
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Selecting the Correct Capacitor and Resistor Values for an HSE Crystal on an STM32F446RETx
I am currently working on a PCB that involves an STM32F446RETx microcontroller. I've encountered some difficulties in selecting a suitable 16MHz HSE crystal oscillator.
Since my intention is to order ...
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MEMS Oscillator Simulation in LTSPICE
The MEMS oscillator topology i simulate is below
fig1: Oscillator schematic
Source: A Tunable-Gain Transimpedance Amplifier for CMOS-MEMS Resonators Characterization
Below is mine, the resonator i am ...
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My LC tank circuit doesn't seem to work as a RF generator
I'm trying create a super simple frequency generator to create RF in a specific frequency (for sending Morse code). I have a HF SDR receiver which I use to see waterfall of frequencies.
Based on this ...
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Datasheet of ECS-2200B 10 MHz oscillator
I have problem finding information about this oscillator. I can't find what is the activation time when the control pin 1 is put HIGH. In the datasheet the only thing I found is start up time which is ...
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Improving waveform shape in discrete Pierce oscillator with Schmitt trigger output
I am making a simple clock source using discrete Pierce oscillator with its output attached to high speed Schmitt trigger buffer to get square wave in the final output.
I got the circuit for the ...
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AM Radio Transmitter
I have been trying to make an AM transmitter and I found this schematic from a persons college project. I understand what is circled in red but the rest I am struggling with. The part circled in red ...
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What is the waveform of crystal oscillator and RTC and how can I monitor it?
I'm trying to study crystal oscillators for STM32F103CBT6 and getting unexpected results or confused whether it is correct or not.
https://youtube.com/shorts/AmvjPQYd41o?feature=share
I expected that ...
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Is this a working way to design a sequencer and an oscillator connected to each other?
I would like to build a sequencer that controls an oscillator. I attached the schematics. The basic principles are that R_1 and R_2 are chosen, so that they yield a voltage of 0.7V at point D ...
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Should I also implement a CMOS clock oscillator's load circuit to my PCB?
I am trying to use a CMOS Clock Oscillator (SM7745HEV) as a clock input for my ADC. When the clock arrived, I tested it with an oscilloscope to verify its frequency. As shown on the datasheet, I used ...
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How to diagnose a possibly failed crystal?
I'm trying to repair a Panasonic SA-PMX70 audio system and I have narrowed the issue down to a DAC/DSP IC ("BU9447", proprietary, undocumented) which does not seem to be responding at all. ...
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FM receiver with 2N3904
Please explain how these 2 transistors work.
I don't understand how it active an amplify the signal.
Source: https://circuitdigest.com/electronic-circuits/simple-diy-fm-receiver-circuit-on-internet
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Problem generating two asymmetrical pulse waves
I am trying to generate two pulse waveforms with a on to off time ratio of around 40/60. The max amplitude is only 5 V however the switching frequency is quite high at around 100 kHz.
The two ...
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Should I parallel unbuffered inverters in a CMOS crystal oscillator circuit?
I want to use a 74HCU04 unbuffered inverter oscillator circuit as a digital clock source on a PCB, as referenced in this TI app note:
Appnote SZZA043
It's mentioned in the note, the inverter gain is ...
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TCXO output load
I’m using a 40 MHz TCXO to drive the clock input of an A/D chip. The output of the TCXO is DC coupled 1.8 V LVCMOS and it is specified in the TCXO datasheet that the output load is 10 pF // 10 kOhm. ...
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Issue with 100 kHz astable multivibrator
I am trying to design an astable multivibrator to deliver an output frequency of around 100kHz. My requirement is to effectively toggle between two inputs (say A and B). They can’t be on at the same ...
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Are there industry standards for incorporating a 10 MHz reference signal input into a design?
Are there any industry standards for accepting 10 MHz reference input signals into PCB designs? I've read about standard power levels (as in, 13 dBm at 50 ohm input impedance) in a few forums, but I'm ...
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Regulating output of 555 astable oscillator [duplicate]
I need to build a circuit that takes a 12v DC input and produces a 5v DC 30Hz square wave.
My thinking is to produce the square wave using a 555 in an astable oscillator configuration, and then step ...
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Is this supposed to be the output of this circuit?
I used LTspice to simulate a oscillator circuit to convert DC to AC. The oscillator is then connected to a class AB power amplifier to increase the circuit current. The load of the Class AB amplifier ...
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Output load capacitance vs max input load capacitance
I am currently in the process of building a frequency divider circuit. To realize a lower frequency of 3.072 MHz. I use the: ECS-TXO-3225MV-122.8-TR
For frequency division and reduction I use D-...
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How can I design two CMOS ring oscillators so that I can observe sub harmonic injection locking?
I am trying to design two CMOS ring oscillators for the purpose of observing sub harmonic injection locking. I want the injection frequency to be two times the locking frequency. I have designed some ...
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How to properly connect oscillator circuit to amplifier?
edit v2:
Schematics:
The ic on the left is a 40106, and the thing inside is a Schmitt trigger with inverting output.
In 'edit v1' below you can see a wiring diagram.
edit v1:
Rough schematics and ...
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3V oscillator to 5V µC with an 74HCT inverter (12.8 MHz) - bad idea?
I'd like to use an AVR (ATmega328P-AU to be precise) in combination with a fairly accurate oscillator for timing purposes. I stumbled upon the fact that oscillators which have greater accuracy mostly ...
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How do you design a crystal oscillator circuit for STM32F4 MCUs
I am trying to choose a crystal and accompanying capacitors and resistors for use with an STM32F4 MCU's high speed external clock. I've decided to use a crystal with 8MHz frequency and 10pF load ...
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Why does my oscillator circuit + class AB power amplifier circuit not work?
I am trying to design a oscillator circuit + class ab power amplifier for my circuit. I tried simulation on ltspice but it did not manage to work. I have problem figuring out what is wrong with my ...
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How to change the transmitting frequency of a FS1000A module?
I have tried swapping the 433 MHz crystal on a FS1000A module for an 868 MHz one, since this is the frequency my garage operates at. Now the modified module does not work reliably. I did get it to ...
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Ring Oscillator
I was wondering if it was possible to build a single stage Ring Oscillator using only one inverter. I found that it is not possible because the absence of delay, but could someone please explain me ...
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Using inductor on PCB component power rails
Here is excerpt of a schematic from an FPGA board. It shows some ICs that generate clock signals. This implies a whole lot of switching activity.
I assume based on what I know about power supply ...
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Crystal distorted wave
I am using ECS-250-18-30B-JTN-TR crystal with two C0G/NP0 18pF capacitors as loading caps. The crystal is used with WIZnet W5500 chip. When I observe the shape of the sine wave coming in and out of ...
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How to make a quartz clock that does not stop
We are an association of French students learning electronics. I'm actually making a circuit to make a quartz clock, I'm looking over the schematic that I found on the net, but I really don't know why ...
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"SCR triggering using line-synchronised UJT relaxation oscillator" circuit not working with full wave rectified single-phase supply
Circuit Diagram:
We implemented the aforementioned circuit, and the relaxation oscillator is working fine. However, the load voltage waveform (load hooked with SCR anode) is the same as the rectified ...
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Square, Triangular and Sinusoidal Wave Generator with AmpOp and Diodes
I'm having trouble building a circuit to generate square, triangular, and sine waves. In theory (calculations), everything is correct, and in the simulation (done in LTSpice) everything is also ...
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Best way to close GPSDO PLL digital loop?
I am trying to build a GPSDO with a holdover capability of 500us/24hs (maximum drift accumulated).
The system uses a 10MHz OCXO and it is my intention to use a microcontroller (ATMega, STM or ...
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What does a typical oscillator circuit look like?
I would like to change a crystal oscillator circuit to an oscillator IC like this. Below is the image of the original crystal circuit.
simulate this circuit – Schematic created using CircuitLab
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The ferrite bead at where the supply pin of crystal oscillator is
I have a question about ferrite beads. The DC resistance of the ferrite bead is an important parameter for picking up our design. This value has to be as low as it can because if the current drawn ...
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Adding LC filter to PNP circuit
Let's say I want to add a L1C1 filter to power supply of PNP oscillator to avoid a current spikes drained from battery.
In case of NPN circuits the designers usually place the L1 to Vcc rail.
However, ...
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Self Drive Piezo Element/Self Excited Piezo Element Circuit
I have a self drive piezo element/self excited piezo element that I want to resonate at about 1-2kHz. As of my understanding, by using a circuit like in the figure below, the element will resonate at ...
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Noise generator or sweep genetor instead of tracking generator
My spectrum analyzer tek 492 does not have a tracking generator. I have HP8350B in my eyes (to buy) but can be sweep oscillator used instead of tracking generator? So far i understand TG is at the ...
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Why it is oscillating? is this self oscillation? how to remove
Hello i have an circuit (2 stage op amplifier) with an resonance coil on input. I give an impulse on the coil and the circuit start resonating at frequency 1khz for seconds.
How i can change the ...
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Purpose of one-sided carrier suppression in DBM phase detector for cavity stabilizer
I am trying to understand a circuit taken from the link below. In the article they use a double balance mixer as a phase detector.
I have simulated the DBM mixer as a phase detector, results are shown ...
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Understanding Crystal Oscillator with 3 BJTs
I came across this oscillator circuit.
I can't figure out how it works. Ok, there is a differential pair Q1, Q3 with a tail resistor R4... Everything else is out of my comprehension (it doesn't ...
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stages vs. frequency analysis of ring oscillator
I am currently working on ring oscillators and have stumbled across the following doubt.
Upon practical analysis of CS-amplifier based ring oscillators on hspice(the not gates are comprised of CS ...
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Flyback energy from coil flows back to source (high power pulse generator)
I am charging a coil to 2A, then (after BJT off) I want transfer this energy to cap to get a rounded L2 coil pulse (voltage). The coil pulse will be used to wireless signal transfer.
This generator is ...
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Barkhausen Stability Criterion and when feedback can be considered positive
My analog design book says the following:
"As a signal \$ S_\epsilon \$ propagates around the loop and returns to the summer \$ \Sigma \$ as \$ S_f \$, it experiences a frequency-dependent phase ...
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Can I use a 50MHz external oscillator for an ESP32-D0WD-V3?
Can I use a 50MHz external oscillator for an ESP32-D0WD-V3 instead of a 40MHz external oscillator? I only have 50 MHz at hand.
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Hardfault STM32 on SystemClock_Config()
I have a custom board with a basic crystal oscillator connected to the High Speed Oscillator pins of my STM32F446RET6.
I assembled 2 boards and found out only 1 board works fine but the other does ...
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How do I identify the value of a crystal oscillator?
How do I discover the frequency of a two-pin (to be used with two through holes) silver crystal oscillator which is inscribed with only:
...
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