Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [oscillator]

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

-1
votes
0answers
26 views

Clock Generation for Timers [on hold]

Can anyone explain me the complete flow of Timers from oscillator signals to clock used for Timers. How the clock is generated and used in timers for event capture and Time elapsed? The amplitude of ...
0
votes
0answers
57 views

How could using an op-amp on the output increase the frequency of an electronic oscillator?

I am trying to send an input from a 5 MHz Colpitt oscillator through an op-amp configured as a 10x gain buffer. We are connecting the collector node of a common base Colpitts electronic oscillator (...
1
vote
1answer
45 views

What's the source of this noise in my Arduino oscillator?

I've been experimenting with techniques to rapidly switch on and off the digital output pins in an Arduino. This is the code I use: ...
1
vote
0answers
35 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 ...
0
votes
2answers
52 views

3.3V Oscillator AC couple to 1.5 Vp-p input

I'm using MICRF220 (origin from MICREL, now Microchip, Sadly, I can't find a suitable place to ask my question. It seems Microchip has not a suitable forum for this chip yet!!!) It can receive ...
-1
votes
0answers
52 views

Oscillator Interference [closed]

a friend of mine and I have recently begun creating synthesizers and such. After testing out a standalone 555 ic oscillator on my guitar amp I found it created a lot of interference. I can easily ...
0
votes
2answers
87 views

Need help understanding an electronic oscillator (Schmitt trigger + capacitor)

When we use this circuit, the LED blinks. I know an inverter transforms high to low voltage and low to high voltage, but here the voltage source is connected to the inverter all the time so the ...
0
votes
3answers
55 views

Best oscillator topology for a ultrasonic sensor? [closed]

I want to know which oscillator topology is the best to work for an ultrasonic emmitter signal. This means it has to work at a 40 kHz frequency. I've already tried a phase shift oscillator and ...
0
votes
2answers
67 views

Wien bridge slowly decaying oscillator

I want to build a resonator that slowly (~3 seconds) decays without a stable oscillation. I've tried using a simple RLC circuit without luck - I've got ~1-2ms decay time at maximum; so, I've turned my ...
0
votes
0answers
32 views

Simple oscillator design not working when implemented

I thought this would be a quick build, but maybe there is something wrong with the design. Even though no waveform occurs, the MOSFET gets very hot. f = 1/(2π√[C(L1+L2)]) An n-channel 2N7000 MOSFET ...
0
votes
0answers
30 views

Simplest schmitt trigger with fewest part count for microcontroller

I own several AT89C4051 microcontrollers and I'm currently trying to read signature bytes of the micros that I probably broke (by applying 7.2V to the VCC pin before noticing the 5V regulator became a ...
0
votes
2answers
75 views

Help with an oscillator implementation

I want to simulate a simplistic "Van der Pol oscillator" in a circuit simulator such as LTspice or circuitLab. The only circuit I found is the following: But this requires negative resistance ...
1
vote
4answers
103 views

What happens if the frequency of the receiver osc does not match (exactly) the carrier frequency?

I thinking about FM and AM. Theoretically the carrier frequency is perfectly match the demodulation frequency. But what happens if there is a mismatch? I think using AM the frequency of the base-band ...
0
votes
0answers
38 views

Minimalist high speed 8051 microcontroller testing circuit on breadboard

I'm trying to come up with a circuit using the least number of parts possible to build on a breadboard that tests the basic functionality of a microcontroller, specifically the AT89LP4052 ...
2
votes
1answer
72 views

Separate GND-plane for microcontroller crystal resonator

1.  Background info I'm designing a board for an STM32F767ZI microcontroller. This microcontroller has a primary oscillator for the SYSCLK (overall system ...
0
votes
0answers
44 views

What would be an appropriate oscillator crystal for an STM32F042C6T6 given the following circuit?

I am building the circuit for a CAN interface for Linux following the schematics for the CANalyze hardware. I have sourced every component for the build except the crystal oscillator. The schematic ...
0
votes
2answers
53 views

Calculating the oscillator frequency

I am trying to calculate the frequency of the internal oscillator, in order to go through the design procedure listed in the datasheet. The problem is that it gives me answers that contradict the ...
6
votes
3answers
1k views

Difference between internal and external oscillator for a microcontroller?

I am a beginner with respect to microcontrollers, so I just want to ask is there two option for choosing the frequency of the microcontroller: to be internal or external? If there is internal ...
1
vote
3answers
60 views

Maximum CPU Frequency of PIC24FJ256GA705 That I Can Get with 8MHz Crystal

I'm used to run PIC24 device family (e.g PIC24FJ256GB) at CPU freq 32MHz using the PLL. Recently I got to use PIC24FJ256GA705 on my new project and when I read the datasheet, I found out that the PLL ...
2
votes
2answers
2k views

Why does this simple circuit oscillate? (Ekasi oscillator)

Why does an Ekasi oscillator oscillate? From my research, I learned that when this is first plugged in, the capacitor is charging, so the LED doesn't shine. When the capacitor reaches 12v, then the ...
1
vote
1answer
62 views

How does the computer's BIOS change the clock speed?

A computer's BIOS can change either the multiplier value or the (FSB) clock frequency to overclock or underclock a CPU. While overclocking by changing the multiplier value is easier and in more often ...
1
vote
1answer
51 views

IF in superheterodyne receiver

I have a radio which uses CXA1619 IC. I have a question about the oscillator of this IC. There is a gang capacitor in the circuit for tuning RF and oscillator and there are two different trimmer ...
0
votes
2answers
62 views

How to massively reduce the frequency of a ring oscillator?

Say a ring oscillator which involves 9 inverters and outputs a frequency of 1Ghz. What would be the best way to get an oscillating output of say 10 Mhz from this. My initial thought is using D type ...
3
votes
3answers
120 views

How to initiate a ring oscillator

So assuming it's a simple oscillator like so : How can I start this oscillating with an initial value then make sure this value doesn't affect the operation of the circuit?
0
votes
1answer
38 views

Controlling a ring oscillator with a signal

So for example if you have a very simple oscillator such as: How could I control this so that the oscillator is only in operation when a signal (x) is high. And not in operation when it is low?
0
votes
0answers
28 views

Derivation of current starved inverter

I'm working on a design of a ring oscillator with current starved inverters. Now, I wondering how can i get the formula that describe the drain-source voltage Vds of M4 and Vds of M1.
0
votes
0answers
65 views

BJT Astable multivibrator problems

simulate this circuit – Schematic created using CircuitLab I am trying to build an astable multivibrator that's tunable to around one megahertz. I am using 2n2222 and 2sc6082-1e transistors. I ...
0
votes
0answers
40 views

LC oscillator changing L

I have a question regarding a LC circuit. I was experimenting with a coil and changed the capacitor (eg. 1uf, 4.7uf, etc) in a usual LC parallel circuit. I charged the capacitor and then measured the ...
5
votes
3answers
145 views

Soft latching power switch

I have stumbled upon a soft power switch with low part count on EEVBlog, which I found very interesting for my hobbyist projects: https://www.youtube.com/watch?v=Foc9R0dC2iI Since it uses a PMOS and ...
0
votes
2answers
75 views

Transistor as variable resistor in LFO

I've constructed a basic dual op-amp LFO as in the below circuit simulate this circuit – Schematic created using CircuitLab The variable resistor R5 is used to alter the rate of the LFO, I'm ...
0
votes
1answer
56 views

Help identifying type of LC oscillator

I am trying to understand the RF transmitter (Q1) part of this schematic: (source: https://fccid.io/KUJCE9001/Schematics/Schematic-Diagram-171495.pdf) What type of oscillator is it? Colpitts, Harley,...
1
vote
2answers
99 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-...
-2
votes
3answers
104 views

What kind of voltage controlled oscillators are convenient to obtain very low frequencies?

I'm planning to make an oscillator which can have a range between 0.1Hz to 100Hz or at least 1Hz to 100Hz. I know it is a huge topic but is there an analog IC family for such purpose? Something ...
1
vote
1answer
33 views

MCU with single external clock pin

I am selecting an MCU (EFM8BB10F2G-A-QFN20 Datasheet here) for one of my projects and I found a strange thing. This MCU has only pin for external clock source: Till now, I have never encountered this ...
0
votes
0answers
26 views

Oscillator circuit based on a SAW delay line

I was hoping someone may be able to point me in the right direction for a oscillator circuit that depends on a SAW delay line for control of the frequency. The SAW central frequency is 20 MHz, for ...
3
votes
1answer
408 views

Why is this BJT Schmitt trigger producing a sine wave?

I am trying to build a Schmitt trigger from a pair of BJTs to convert a sine to a square wave. The sine wave is from a Colpitts oscillator running at over 150 MHz. I want to measure the ...
4
votes
3answers
201 views

Current source with unlimited cap drive op-amp oscillating

I've been trying to create a current source, and have finally gotten my hands on some LM8261's which should be an 'unlimited cap drive' op-amp. The problem is, it is still oscillating... This is the ...
0
votes
1answer
64 views

Do not understand why current flows in undamped oscillator circuit, and getting troubles in practice

I want to make my own antenna, so I started to make a generator. I found scheme below (only without a K key in the bottom) in internet, and it seems to be exactly what I was looking for. There PNP ...
0
votes
2answers
68 views

How to limit the output voltage of a TCXO?

I am using an SiT1552 MEMS TCXO providing 32.768 kHz. It will be sourcing two ICs: a microcontroller and a DA14580 Bluetooth Low Energy transceiver. The ICs and TCXO are all powered by 3.3V. The TCXO ...
0
votes
1answer
50 views

How to connect the PHY crystal for RMII?

I'm attempting to implement Ethernet communication for the first time and have run into an issue with my PHY. I'm using the KSZ8091RNBCA. According to the datasheet, when running in RMII mode, the XO ...
0
votes
0answers
35 views

LC oscillator emitter current doesnt go to 0(class C)

Im trying to create a 433MHz oscillator with the help of ADS for the simulation. From the lectures i have had on transistor LC oscillators, i know the are forced into class C operation, and that ...
1
vote
0answers
49 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: ...
0
votes
1answer
59 views

Why doesn't my charge pump work with 1.5v supply?

I have been trying to get the following circuit to work with 1.5V AA battery but it does not work, even though it works fine with a 3.3v supply. I built the multivibrator circuit by discrete ...
1
vote
0answers
54 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
37 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 ...
2
votes
1answer
72 views

PIC18F25K50 - 48MHz with internal oscillator does not work

I'd like to run a Microchip PIC18F25K50 at its maximum speed of 48MHz from its internal oscillator. Here is the overview of the oscillator system from the datasheet: The 16MHz from the HFINTOSC can ...
3
votes
2answers
491 views

Help needed in understanding this LED chaser circuit

Here is a circuit called LED chaser that I found the other day. I watched some videos on Youtube and saw that its function is to blink the LEDs in some kind of sequence: https://www.youtube.com/watch?...
0
votes
1answer
52 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 ...
0
votes
3answers
204 views

LTSpice is frustrating me. Why isn't this Class C amplifier working? I can't get a sinusoudal output

I've been trying to research how a class C amplifier works, and it makes perfect sense to me, but I'm having problems getting it to function in LTSpice. I have the latest LTSpice version (XVII with ...
5
votes
3answers
376 views

Kickstarting an opamp for oscillating?

I have been building many different variations of op-amp oscillators but have come across a recurring issue that has manifested itself again in this VCO schematic: I find that when turning on my ...