Questions tagged [oscillator]

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

153 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
3
votes
0answers
115 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 ...
3
votes
1answer
177 views

What is the purpose of the following inverter topology?

I stumbled upon an Schmitt-trigger oscillator circuit. I can fully understand the principles and its function, but what I cannot fully understand is the chain of inverters after it. In the above ...
3
votes
1answer
182 views

Is it the crystal / quartz?

I have a simple gadget (called "Fridgezoo") that talks when the fridge stays open. I always hated it, but my sentiments are with it (hey, it talks!) so I want to repair it. What's the problem? It ...
3
votes
2answers
408 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-...
3
votes
1answer
52 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) ...
3
votes
1answer
463 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 (...
3
votes
1answer
324 views

LC Oscillator Gain Compression

I am designing an LC Colpits common base Oscillator for the FM broadcast band. The project is going to be extremely low radiated power as I will only be using it in my car. I am currently using this ...
2
votes
0answers
73 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 ...
2
votes
2answers
134 views

Oscillator capacitors to VCC

I recently came across this circuit in which the oscillator capacitors are connected to VCC and not to GND. Researching I've read many comments stating that VCC and GND are at the same AC potential. ...
2
votes
0answers
262 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 ...
2
votes
1answer
405 views

Can someone explain how this oscillator circuit works?

I've started learning about transistors and I've created this circuit. The circuit works, I'm just trying to understand how exactly it's working. From what I can understand, the absence of current ...
2
votes
2answers
227 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 ...
2
votes
1answer
208 views

How and Why Does this Oscillator Work?

I am a beginner hobbyist, trying to understand a circuit from an old Radio Shack electronic snap kits game (the game variant I have is "electronics 303", and the circuit is project #202 : Oscillator 0....
2
votes
0answers
518 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
votes
1answer
963 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
votes
0answers
1k 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 ...
2
votes
0answers
92 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
votes
1answer
579 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&#...
1
vote
0answers
74 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). ...
1
vote
0answers
48 views

Powering crystal oscillator (not the uc's one) using one of microcontroller pins for power saving

I want to design a low power RF link using SI4463 and I just need to send data but when I was searching for a crystal oscillator found out that most of them consume about 2-5 mA current. Is it ...
1
vote
0answers
57 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, ...
1
vote
1answer
72 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 ...
1
vote
3answers
136 views

Selecting a damping resistor for crystal oscillator circuit

I'm building a data acquisition board with an ADAR7251 ADC. I'm trying to figure out the crystal oscillator circuit, and am stuck on the damping resistor. The relevant datasheet is https://www.analog....
1
vote
0answers
103 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 ...
1
vote
0answers
66 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 ...
1
vote
1answer
137 views

Calculating Rs Value for 32kHz Pierce-Gate Crystal Oscillator Circuit

Edit: My primary objective is to learn the mathematical model to compute the load resistor \$R_s\$ to satisfy a given crystal's drive level, not just fixing the one instance below. I'm building a ...
1
vote
0answers
49 views

Clapp Oscillator Oscillating Frequency Strongly Dependent on the Transistor

For temperature sensing purposes, I have been challenging myself to design a dual mode crystal oscillator operating at the frequencies 30MHz and 90MHz (fundamental tone and the third overtone, ...
1
vote
1answer
52 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
1
vote
0answers
46 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 ...
1
vote
0answers
62 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 ...
1
vote
2answers
79 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>...
1
vote
0answers
50 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 ...
1
vote
2answers
65 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 ...
1
vote
3answers
117 views

Does Crystal/Oscillators package matter?

I design a lot of PCBs that uses microcontrollers with external clocks. For some reason a lot of the example designs always tend to use the big generic HC-49 package. Even factory made modules that I ...
1
vote
0answers
156 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 ...
1
vote
0answers
145 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: ...
1
vote
0answers
61 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: ...
1
vote
1answer
95 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 ...
1
vote
1answer
201 views

Crystal reference and capacitors for w5500

I'm selecting the caps for the crystal oscillator of the wiznet W5500. The standard Load Capacitance for 25Mhz crystals is 18pF. I found out that the hardware guideline claims for a Load Capacitance ...
1
vote
0answers
155 views

Put the crystal on the bottom with thru-vias, or on the top with a blind via?

I'm using an STM32L155 in a very small (0.4 mm pitch) WLCSP package (6x9 array). At this scale there is no room for traces between the balls, so the design requires HDI and/or blind vias to fanout the ...
1
vote
0answers
61 views

Phase Shift Oscillator Feedback Gain

I'm having trouble getting to the result of the feedback gain (β) of the following phase shift oscillator: Is the circuit correctly designed? How do I calculate the feedback gain? Edit: Is it ...
1
vote
2answers
141 views

Current canceling circuit

I have a question that I hope you can help me with. In schematics below an oscillator is presented that is fed with both AC and DC voltage, to be polarized and to induce movement of it. At the output ...
1
vote
0answers
94 views

Designing a resonator circuit: drive level considerations?

When you design an oscillator circuit for a Quartz crystal, you have to take the maximum drive level of the crystal into consideration and add a damping resistor to keep the actual drive level below ...
1
vote
0answers
136 views

Unstable Oscillation in Pierce Oscillator

Here is a Pierce Oscillator that I built to oscillate at 16 MHz. I put the parts on a breadboard (I know its a bad idea, but this is what I have with me). And here is the result: As we can see I am ...
1
vote
0answers
50 views

Noise in opamp amplifiying circuit which can be removed by short-circuiting VDDA and GNDA?

I have built a filtering and amplifying circuit for an ultrasonic receiving channel. The schematic is shown as below. The +3.3V is the power supply of a microcontroller. It amplifies the receiving ...
1
vote
0answers
108 views

How does this circuit oscillate?

I once found out that basis of this circuit looks like a Royer oscillator. What makes this circuit oscillate? Especially, it is still not clear in my mind that what is the function of capacitors and ...
1
vote
1answer
364 views

Maintaining phase continuity of LO when switching from Tx to Rx mode

I am building a two-way communication setup based on software defined radios. Setup: The Tx needs to send a sinusoid to the Rx, and the Rx - after some processing - sends its own sinusoid in return. ...
1
vote
0answers
408 views

dsPIC33 Fcy is half the desired frequency

I'm working on a dsPIC33EP64GS502 trying to make it work at 70 MIPS with the internal oscillator. This is my code: ...
1
vote
1answer
952 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 ...
1
vote
0answers
284 views

2.45 GHz frequency generation

I have designed RF-PA and to test the circuit, I want to design an oscillator which can give me a 2.45 GHz continuous wave. What are the simplest ways to design such a circuit? What are the ...