Piezo-electric device cut at a specific resonance frequency, mostly used in oscillators.

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47 views

Can Two Or More ATTinys Share One External Crystal? [duplicate]

I've got two I2C Slave ATTiny85 chips both running at 16MHz with external crystals. Can they both share a single crystal with the 22pf caps? Is there anything wrong with this? I don't have any free ...
3
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2answers
1k views

What generates the clock signal in a fast CPU and how does it work?

Often, for integrated circuits, a quartz crystal is used to generate the clock signal. However, this only reaches speeds in MHz. What component, or what circuit, generates signals up to 5 GHz ...
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2answers
84 views

Why LED signboards shake when I eat an apple? [duplicate]

while I was sitting in city center with so many LED (especially red ones mounted) signboards and I was bitting an apple, the signboards suddenly begin to shake for only a second while my head is ...
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2answers
29 views

Charge Cap Crystal - Package

I got an external crystal for a MCU ( tm4c1233h6pm). I use the NX-16MHZ from NDK, in the datasheet, the recommend cap charge for the crystal are 2 cap of 10 pF for a 16 Mhz crystal. My question is ...
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1answer
67 views

Atmega328P 32.768KHz Crystal Issue

I am having an issue with 32.768khz crystal connected to an Atmega328P (which I am using as an external source to timer2 in asynchronous mode to wake up the Atmega from sleep every second). On a ...
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1answer
51 views

Can I use a series crystal in an parallel crystal optimized oscillator?

Based on this application note from Maxim Integrated in section "Resonance Mode": "Crystals have two modes of resonance, parallel and series, and all crystals exhibit both resonance modes. The ...
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3answers
67 views

Capacitor rated for 100vdc on 5vdc board

As the title says, I have capacitors rated 100VDC 18pF. Can I use these on a board that uses 5V Max ? I can't really find any direct answer to that question. What I want to do is to put a crystal to ...
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1answer
84 views

Crystal PCB track

This is my current PCB crystal set up. The crystal run at 16 Mhz. Any thoughts/comment? Links: MCU - Datasheet TI PCB guideline Tiva C - Here
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2answers
108 views

NEED HELP: Oscillator Error and PIC24F stopped working

I have a 30MHz Crystal Oscillator to clock a PIC24FJ128GC010 Controller. I am programming in MPLAB X. My idea is to generate a pulse on one of the I/O pin toggling. But unfortunately, I cannot do so. ...
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1answer
70 views

Crystal oscillator frequency Vs size?

What is the relationship between crystal oscillator frequency Vs Die size? Why it is smaller Die size over the high frequency ranges and bigger Die size in lower frequency ranges?
24
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4answers
5k views

Why do we use 32.768 kHz crystals in most circuits?

Why do we use 32.768 kHz crystals in most circuits, for example in RTC circuits? What will happen if I use a 35 or 25 kHz crystal? I assume because the IC internal Xin, Xout pin circuitry should be ...
4
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3answers
508 views

SMD Crystal solder(?) problem and any recommended test procedure

I use a 32.768 kHz SMD crystal (datasheet) for a MCU. Here is the layout part of the crystal. Here is a view from an actual PCB I mounted the components by hand-soldering, and produced about 30 ...
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0answers
37 views

Load resistor placement for clock section

I am placing a crystal, associated capacitors, damping resistor and load resistor to a clock section of a MCU. My question is, should the load resistor be placed close to the MCU or close to the ...
2
votes
1answer
70 views

Crystal Footprint Placement

Pretty simple question, please point me in the right direction if this has already been asked. I am designing a board around freescale's IMX23 microprocessor which runs from an external crystal at ...
0
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2answers
43 views

MEMS oscillator how to wire them and can they replace crystals?

My question is: Can a MEMS oscillator replace a crystal oscillator? If answer is yes, how I can wire them to XIN and XOUT? How should I select capacitor? And since they don't have crystal capacitance ...
0
votes
1answer
98 views

stm32f4 HSE crystal

I'm trying to set up an HSE for my STM32f4, using this crystal. but there are 2 pins : OSC_IN and OSC_OUT, but my crystal only has one output. So what do I link OSC_IN and OUT to ?
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2answers
46 views

Correctly choose Crystals and Cext

I've a problem to choose correctly which Crystal to use with an ARM Cortex M4. In particular, I can't understand relationship between datasheet specifics and a Crystal used in an ARM Cortex M4 EVB. ...
0
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3answers
193 views

external crystal not working but internal clock worked normaly in PIC18F45K22

I have designed a PCB based on the PIC18F45K22 microcontroller. I want to use an external crystal (4Mhz crystal with two 22pF capacitors). I can successfully program the code but the PIC won't run. ...
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1answer
114 views

Problems with using 20Mhz crystal withPIC18f2420

I am using PIC18f2420 to generate PWM. I am using Timer 2 with 4MHZ crystal, which works perfectly by giving me PWM. I need to get 100KHZ of frequency for PWM, for which, 4MHZ crystal is not enough as ...
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1answer
167 views

When we need external crystal for atmega?

I created microcontroller circuit, refers to most of circuit in internet. Which is it is using external crystal. As i know now, that atmega16 has internal oscillator by default 1MHz. So, ...
0
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0answers
74 views

Lc tank resonator vs. quartz crystal?

For Colpitts and Hartley oscillators, which is preferable to use: an lc tank resonator, or a quartz crystal? I've built Colpitts oscillators with both an lc tank circuit resonator, and with a quartz ...
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1answer
127 views

How do I deal with different XTAL pin capacitance when selecting XTAL and load capacitors

I'm trying to select a 32kHz crystal and appropriate load capacitors for Atmega48A MCU. Atmega48A specifies different capacitances for Xtal1 and Xtal2 pins: 18pF for Xtal1 8pF for Xtal2 The ...
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6answers
2k views

Why are 32.786Khz crystal cans soldered to PCB? [duplicate]

Every development board I have ever used that includes a 32.786Khz crystal has always had its can soldered directly to board. What is the reason for this ? Is this to minimize radiated energy from ...
0
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3answers
98 views

How does oscillator frequency stability affect timing? [duplicate]

If, for example, a crystal oscillator is specified as +/- 100ppm what does that mean? That the exact frequency is uncertain to that degree, or that the frequency varies by that degree over normal ...
3
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1answer
112 views

One crystal oscillator for multiple clock inputs PCB tracks topology

When sharing a crystal oscillator output to multiple clock inputs, what should the oscillator output PCB tracks topology be ? Should they go from the oscillator output to one clock input to the next ...
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0answers
110 views

Colpitts vs. Hartley?

What are the pros and cons of using a Colpitts or a Hartley configuration for an oscillator?I know that the difference between them is the form of feedback, but does one or the other perform better ...
3
votes
1answer
159 views

Crystal oscillator problem

Here is the datasheet of the crystal (32 MHz) that I use for a MCU. The right layout is an older version of my board which totally works fine. The left one is the newer version where I placed the ...
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0answers
23 views

T/R switch for single element material thickness testing (-200V pulses)

Our non destructing ultrasonic inspection design now has two crystals, one for transmitting and one for receiving. We would like to have only one crystal for transmitting and receiving. This is common ...
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2answers
132 views

XMega Get Clock Speed

I'm doing some debugging on my project and I need to check if I'm setting my external crystal correctly. I have the ability to print out to a serial monitor via usb, is it possible to retrieve the ...
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2answers
288 views

Understanding a simple crystal oscillator transmitter circuit

I've recently built this circuit: http://makerf.com/posts/mighty_simple_shortwave_transmitter It works on the desired frequency as you can see from this video : ...
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2answers
211 views

What makes a crystal oscillation to begin

I'm trying to understand how the Pierce oscillator works. I started from the very beginning and I'm looking into the crystal resonator. Thanks to this answer How does a Crystal work? I've managed to ...
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0answers
33 views

asymmetric oscillator layout

Due to space and redesign time concerns, the crystal I'm using cannot rotate. I'm updating the circuit to hopefully make the clock as robust as possible. I have copper keepout in the dotted area ...
2
votes
4answers
266 views

How do crystal oscillators work with feedback consisting of CMOS inverters?

For a crystal oscillator to work, there must exist a feedback path with properly designed specifications in order for all to work as expected. Broadly, the basic form of this control system is as ...
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1answer
45 views

How to select external crystal in atmega162

How to set AVR to select external crystal for clock? A _delay_ms(1000) is producing a quick beep however it should produce 1 sec beep if it is operating on 12Mhz. Could it be done programatically of ...
10
votes
3answers
606 views

Are there crystals that are tolerant of high pressure?

Are there crystals that are tolerant of high pressure? Or do they all have an open space in their case? A customer wants to use our product in a submarine, immersed in high pressure oil. I ...
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1answer
173 views

Load capacitance for a microcontroller crystal?

I know there are lots of similar questions on here, but I've read many of them and am still a little confused. I'm a student making a board similar to the Arduino Pro Micro, using a Atmega32U4 ...
0
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2answers
104 views

Can one always drive oscillator inputs with a single-pin oscillator output and bypass the integrated feedback circuitry?

Very little is written in the MCP2211 datasheet regarding the oscillator input configurations. The microcontrollers I have been using lately allow you to use the self-powered, single output ...
4
votes
1answer
453 views

Why don't I need to consider trace width for a high speed oscillator crystals?

I have followed some reference designs that uses crystals like 40 MHz for the MCU, and I have not considered the trace width to do impedance matching. The result is that the boards works fine (I kept ...
0
votes
1answer
173 views

Can I run an ATmega on 3.3V with an external 16 MHz crystal? [duplicate]

I have been told that is overclocking or it just will not work, but I want to be sure. And are there any real differences that would effect from this? Any tips and tricks will help, thanks!
0
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3answers
185 views

Can you use your computer to make a radio transmitter? [closed]

I was wondering, is it possible to oscillate the electronic signal emitted from the audio jack on a computer ? Because I would like to somehow create a simple radio transmitter just using my computer. ...
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3answers
150 views

Unexpected resistor for oscillator

Please see these two part of this board : In your opinion, What's the usage of the R32 resistor? also in the AN2867 aplication note has been mentioned: Then we have to put a resistor to limit ...
3
votes
1answer
505 views

Crystal Oscillator not giving correct frequency

I have a 48MHz Crystal Oscillator (see here) that I am using as a clock for my microcontroller (EFM32GG332F1024). Looking at the datasheet for this crystal it seemed to me that the load capacitance is ...
1
vote
1answer
241 views

Value for feedback resistor in pierce crystal oscillator configuration

This question is partially an "understanding english" question and partially and "understanding the pierce oscillator configuration" question. Backstory I'm currently looking at using a Freescale ...
0
votes
1answer
157 views

Atmega32u4 not detected

I have made a Arduino Leonardo clone and have been trying to burn a bootloader into it. I am still unable to connect to the Atmega32u4. It says "Unable to enter programming mode. "Unable to enter ...
0
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1answer
835 views

Choosing between internal oscillator and external crystal- ATXMega32E5

We are working with a modern microcontroller ATXMega32E5, from the ATMEL XMega family. Our aim is to use the UART of the controller for effective communication, with the speed of about 9600 or 4800 ...
0
votes
0answers
81 views

Can I replace crystal input with mems oscillator

I am designing a device that uses a real time clock (RTC) from ABRACON. AB1805-T3. RTC Datasheet: http://www.mouser.com/ds/2/3/AB18XX-30381.pdf The device has the option to either select an internal ...
2
votes
2answers
267 views

Selecting an external crystal for FPGA

Assuming that the FPGA has a clock multiplier to get much faster frequencies internally, what is good choice for an external crystal? Let's say I've got a Virtex 7 class FPGA, and I plan to run ...
2
votes
1answer
135 views

AVR external crystal not working with UART

So I have an ATmega328P with a 14.7456MHz external crystal, full-swing settings, and I'm trying to talk to my mac via UART and an FTDI friend-type device. If I connect AVR Tx to AVR Rx, then all ...
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3answers
62 views

Interpreting Crystal Deviations

I am investigating the accuracy of a crystal mounted on a MCU. The API provided by the MCU manufacturer has a TimeGet48 function that returns a 48-bit number ...
3
votes
1answer
187 views

Understanding the Pierce Oscillator Pi Network

I've been looking at the Pierce oscillator and I think I understand how it operates, but I'm a little unsure of the role played by the series caps to ground (the so-called pi network). I've put ...