Questions tagged [oscillator]

A device or circuit that generates an AC signal at a certain frequency.

214 questions with no upvoted or accepted answers
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885 views

32.768 kHz Crystal Troubleshooting

I'm at my wit's end trying to get a 32.768 kHz tuning fork crystal to work and I don't know what I'm doing wrong. First, some background: I'm using a 16MHz crystal in conjunction with an Atmega 328P-...
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280 views

PCB Layout - Ground Plane Clearance Around and Under Ceramic Resonator

We are using Murata's 4MHz Ceramic Resonator (CSTCR4M00G53-R0) in one of our designs and request help in PCB layout design around Ceramic Resonator. The below Murata's FAQs page suggests not to place ...
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1answer
564 views

How would a transistor's hFE affect a phase shift oscillator?

I have a phase shift oscillator circuit from a drum machine that I would like to reproduce as faithfully to the original as possible. My problem is that the 40 year old design uses a transistor (...
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0answers
358 views

State equations of Colpitts oscillator

I am struggling with the simple oscillator on the picture below. My aim is to obtain system of ODEs or DAE at most for numerical simulation in Matlab. But few issues occured with basic circuit theory....
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1answer
149 views

Astable Multivibrator Circuit Analysis

I have been trying to understand why the following astable multivibrator works, but I've hit a wall. Before I explain what's confusing me, I should mention that I don't have a background in ...
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1answer
58 views

Gunn vs. VCO in terms of phase noise and THD

I am trying to compare the THD and noise phase of a Gunn oscillator and a VCO. I conducted an experiment where I measured both parameters for both devices and came up with the following results: (1) ...
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0answers
68 views

Does UJT work as amplifier?

I had got a question in job interview " Draw a circuit of common emitter amplifier using Non Bipolar Transistor." As the question said Non Bipolar, so I assumed that it might be related to UJT. But ...
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0answers
177 views

Multimeter Always Reads 60Hz Measuring a CD4060 Pierce Oscillator

Using a CD4060 IC I’ve built a crystal oscillator circuit similar to the one in the image. I’m trying to use my klein mm400 multimeter to measure the oscillation frequency so I can get a rough ...
2
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1answer
211 views

Thermal Noise in Oscillators

let's consider this circuital model for an LC oscillator in which the parasitic resistance R is affected by thermal noise (represented here with an equivalent noise current source, according to the ...
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0answers
177 views

How does an op-amp work without proper power supply?

I have built a chua's circuit following this diagram: Source: Kennedy 92(pdf). The rectangle inside NR is and eight pin dual opamp. Then, I remove the 9V battery on the right. It is replaced by a ...
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0answers
594 views

Understanding an oscillator circuit

I'm trying to build a driver circuit for an ultrasonic transducer for fog making. The circuit is required to generate a 1.6 MHz signal to drive the ultrasonic transducer. I have found a circuit which ...
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2answers
365 views

LC circuit current?

Suppose we have a fully charged capacitor and we connect it to an inductor. Capacitor will discharge. Inductor will get the current from the capacitor. Wave form of the current shows that the current ...
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0answers
620 views

Crystal Oscillator Design and “Crystal Drive Level”

I followed the video at the link http://www.analogzoo.com/2015/07/ . The video directs watchers to a tool at http://www.analogzoo.com/lab/pierce_bjt.html to help determine parameters to cause ...
2
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1answer
1k views

Designing a VHF Colpitts oscillator using BJT

I am trying to design an Oscillator circuit which can produce a good sine wave with a frequency of at least 500 Mhz and oscillating voltage of around 10 - 15 volts. The output of this oscillator will ...
2
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1answer
1k views

How to design a pierce oscillator circuit?

I need to design a crystal resonator that can be used as a clock source for a uC. The first design is for an ENC28J60 IC, it's an ethernet - spi module and needs a 25MHz frequency. I tried to follow ...
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0answers
2k views

How to find the resonant frequency of a human body?

I've read that the human body has resonant frequencies somewhere around 50MHz. I also think it would be interesting to look for values in other ranges like 10-100 kHz. I'm wondering how to build a ...
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0answers
95 views

Microwave Oscillator: Both Ports Unstable?

I'm just wondering, for microwave oscillators, I think both ports need to be in the transistor's unstable region. What would happen if just one port were in the unstable region and the other in the ...
2
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1answer
722 views

PIC32MX can't get 80 MHz Clock from Internal RC OSC

I am using PIC32MX795F512L with the internal RC oscillator. By changing the settings of the config, I can get to 60 MHz max. But I can't get to 80 MHz. When I change the config for 80&#...
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1answer
41 views

colpitts oscillator does not work with small inductance

Hi I am trying to build a colpitts oscillator with frequency of 10K Hertz. This circuit works fine with L2, C3 and C4 as they are in the picture. However, there is no way I achieve 10mH of inductance ...
1
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1answer
42 views

Can a non-modulated / continuous carrier be heard in Superheterodyne receiver? Why do we need BFO?

I think a continuous carrier be able to heard in a super-heterodyne receiver, since it has it's own oscillator. Why do we need BFO then? What's the difference between the two? So, morse codes would ...
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0answers
42 views

Positive feedback loop in the Wien oscillator

Let's say you got this circuit given which works as a Wien oscillator. To my understanding here Ri is the negative feedback loop and the total impedance of R3 & R4 & L2 & R1 are the ...
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1answer
48 views

Ceramic resonator instead of LC tank in a quadrature demodulator

I'm new to analog circuits. I have a simple question. Can I use a 455khz ceramic/crystal resonator instead of LC tank on a quadrature demodulator input of MC3357? Thanks.
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0answers
65 views

How does only transistor and inductior without a capacitor oscillator work

It has been more than 10 years, I left electronics. I saw this circuit of wireless power transfer, it has to do with induction, but the oscillator circuit shown doesn't contain a capacitor. can anyone ...
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0answers
51 views

Why can't I connect an external clock oscillator to an ATMEGA64A-AU?

I've decided to change my crystal oscillator for one of those smaller (and also expensive-er!) SMD clock oscillators on ATMEGA64A-AU. I've found this image on the web, which seems right: So I built ...
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0answers
56 views

Opamp oscillator kick start

We have this oscillator and for it to run the initial condition is Vout to be V+. How is this done? Shouldn't it be equal to 0V from the schematic?
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0answers
51 views

Impedance matching on oscillator

I have built an oscillator configuration at 4-7GHz. At 5.29GHz, the output of the oscillator has resistance R=-189-j*51. How can I use impedance matching and a bandpass filter since I have a negative ...
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0answers
64 views

Adding a CV in to a simple oscillator

I am using an XR2206 IC to make a simple oscillator module. The documentation shows that it has a VCO as a part of the IC, and uses a variable resistor loop and a capacitor loop to control frequency. ...
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0answers
45 views

PIN Diode Switching

I am using a Skyworks APD0505-000 PIN Diode as a switch for a bank of capacitors for my oscillator circuit at 4-6GHz. I use the Shunt SPST Switch configuration from the manual, but I can't get the ...
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0answers
65 views

How to specify the start up condition in an oscillator simulation using Cadence Virtuoso?

A real oscillator starts oscillating when there is some noise injected into its input. However, in Cadence virtuoso, how can I inject some noise into the input of the oscillator and make it oscillate?
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42 views

Multiple inputs into the base of a single FET

I've been wondering if the below configuration would work: essentially using a single FET (instead of a 3 input OR gate) to determine if a clock signal can be read by a sequence of binary counters: ...
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1answer
72 views

Bipolar RC Oscillator does not oscillate

Falstad schematic and simulation VCC is 9V. I made hardware version of this first (didn't put too much effort in this simulation) and it's not working. I could read about 3-4 V on CE, so transistor ...
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0answers
95 views

Is it really necessary to ground the metal can on crystal oscillators?

I am modifying a KOSS portable dvd player into a portable raspberry pi computer and have noticed that they grounded the can of the crystal that feeds their microcontroller. I am curious if there is an ...
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1answer
39 views

This clamping circuit output is -ve compared to what is expected?

Clock Pulse of Vpeak =10. Providing that the first cycle is -ve why does the output in first is -20 then 0 then -20 and so on? I expected it to be 0 and 20.
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0answers
122 views

Finding Quartz Crystal Datasheets and Choosing resistors for Pierce Oscillators

I am trying to build a 2Hz oscillator using a CD4060 IC and a 32.768kHz quartz crystal for a digital clock project. The schematic below is from a hackersbench article. I've circled the part i'm ...
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0answers
118 views

“Interpolation” oscillator working principle

I was reading Soviet amateur electronics magazines and stumbled upon an interesting oscillator. It uses two high-frequency crystals (27.14 and 26.67 MHz) to to get a low-frequency output (465 kHz). ...
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0answers
68 views

How would one classify a ring oscillator?

This may be obvious to some, but how would one classify a ring oscillator (see figure below of a ring oscillator)? For example, the Wikipedia page, https://en.wikipedia.org/wiki/Electronic_oscillator, ...
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1answer
125 views

Measuring the quality factor RLC circuit

I am trying to get the Q factor for this circuit but I don't know how to simulate it properly. I did a frequency sweep from 1 Hz - 30 MHz. The oscillating frequency is 16 MHz. I can't get the ...
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0answers
122 views

Power efficient oscillator topologies?

I'm building an oscillator for a battery powered capacitive position sensor and I need it to have a high swing (>800 mV) at the output while keeping power consumption low enough. I'm feeding the ...
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0answers
293 views

Design and simulation of cross coupled oscillator in ADS

I am currently designing a low power consumption and low phase noise VCO in ADS. But while performing the transient response I'm not getting the oscillating waveform in the output. I have attached the ...
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0answers
673 views

Load capacitance of the crystal: what is the practical difference between devices?

There's a lot of info and guides on how to select and calculate load capacitors for the parallel resonant circuits. They all assume that people do already possess crystal, and know its CL. That CL ...
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1answer
200 views

What is the difference between residual phase noise and absolute phase noise?

Studying the characteristics of an oscillator with a phase noise analyzer, but I don't quite understand the difference between absolute and residual noise. Any help would be greatly appreciated
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0answers
85 views

Astable multivibrator inverter

I'm new to electronics and trying to make an astable multivibrator oscillator. The PSpice simulation doesn't work (it says netlist error when I place a mosfet or a diode) and I get a really low ...
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0answers
194 views

Understanding a ZVS Oscillator in-depth

For a project I've been building, I've been using the (overused) ZVS oscillator that can be found online. So far it's been working great transferring power wirelessly, but I'm interested in ...
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2answers
109 views

Doubt about Phase Locked Loop

How is it possible that the Signal Output will have the same frequencies as the Reference Signal?\$f_1\$, Frequency of the Reference Signal;\$f_2\$, Frequency of the VCO. Let's assume that \$f_1>...
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92 views

What is the difference between BAW and SAW?

TI has recently (?) released some BAW (Bulk Acoustic Wave) based resonators, but SAW (Surface Acoustic Wave) devices has been around for ages. Most often SAW are found in mobile RF filters. This gave ...
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2answers
93 views

Low-impedance tap in this oscillator circuit

Here is the schematic of Michigan Mighty Mite, a popular transmitter circuit design. It seems to be quite close to a regular feedback oscillator, with a few peculiarities. What puzzles me is the ...
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0answers
359 views

Schmitt trigger oscillators interfere with eachother (74HC14)

I am using a single 74HC14 (hex schmitt trigger) to implement three oscillators. I now have a test build ready and encounter problems. See schematic, it shows component values. Also proper 5V power ...
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0answers
267 views

How can I find the frequency of oscillation of this sawtooth oscillator circuit?

Simple question: how to find the frequency of oscillation of this circuit? simulate this circuit – Schematic created using CircuitLab My attempt at answering the question is the following: ...
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0answers
64 views

Variable frequency of an astable

I have to make the frequency variable of an square waveform generator built with the help of an astable. I modified a circuit a found on the internet and everything seems good with only one exception: ...
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1answer
141 views

Thin plate piezoelectric transducer glued to flat surface in shear mode

I want to glue a piezo plate looking like in the image below such that the wide surface of the plate gets glued onto a flat surface. The image is part of the datasheet from here. If I apply an AC ...

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