Piezo-electric device cut at a specific resonance frequency, mostly used in oscillators.
3
votes
2answers
148 views
How to connect 4MHZ crystal oscillator to get 16MHZ
I've a 10 pieces of 4 MHZ crystal oscillator.
I need 16MHZ crystal oscillator. Can i connect somehow (serial, paralel) more 4MHZ oscillators, and get 16MHZ?
1
vote
1answer
116 views
Will an IC that requires an Oscillator work without one?
I have a PL2303HX and I just etched my board with a USB to Serial IC (PL2303HX). The problem is that it requires a 12 MHZ crystal but I don't currently have.
Just a side note, the IC is on the same ...
2
votes
4answers
140 views
Troubleshoot Crystal Radio
Alright, I'm totally confused. I have built the following circuit with absolutely no result, not even a click. Even after reading through several other similar questions on the board, I haven't ...
4
votes
4answers
320 views
Why aren't 1Hz crystals used to measure seconds?
According to Wikipedia:
Many clocks use a 32.768KHz crystal. Is this because the crystal is smaller than a 1Hz crystal?
If 1.0 Hz == 1.0 second. Then, why the need for the division?
2
votes
4answers
86 views
What kind of oscillator should I use for a binary clock?
I've seen that a lot of clocks use a 32.768KHz crystal. I'm curious why that is exactly. I am working on a binary clock project with some 4520 ICs. I have some 555 timers too, but I want to use a ...
-1
votes
1answer
101 views
Question about transmitter/reciever
I have built a transmitter/receiver with an antenna and crystal. I am wondering if it is stable.
Here is my transmitter:
simulate this circuit – Schematic created using CircuitLab
Here ...
6
votes
3answers
277 views
Crystal circuit works in breadboard but not in perfboard
I'm a beginner and I'm trying to build a digital clock. My clock generator looks like this:
It works perfectly on the breadboard, where I can see the LED blinking at 2 Hz. However, when I try to ...
-4
votes
2answers
177 views
How to make a Transmitter/Receiver [closed]
I am trying to make a transmitter and a receiver, I have two crystals and two antennas (basically a straight piece of metal with plastic covering), how could I make a transmitter and receiver with ...
1
vote
1answer
85 views
Choosing Resonator for AtMega328P design
The ATMega328P datasheet specifies a load capacitance for a resonator from 12-22pF but the only 2 Resonators that will fit in my design (from Digikey) have 10pF and 33pF internal capacitors. Which one ...
4
votes
1answer
195 views
CAN bus bit timing with 16 MHz crystal
I'm trying to receive CAN messages from a radar, whose specification define the following data for bit timing:
...
0
votes
1answer
58 views
RC AM senders/recievers: Changing the crystals, and using Servo PPM as a 1/0 switch
I am trying to use a 27mhz RC car controller to send to an RC Car AM reciever and use that output (short 1-1.5ms pulse of a few mA) to trigger a 5V relay, with the signal stabilised via a ...
1
vote
1answer
393 views
How to configure PIC24H for 20MHz external oscillator?
The basic addition of a 20MHz external resonator is becoming much more painful that I thought. I've got a breadboard setup with a DIP package of a PIC24HJ128GP502. Nothing fancy, and it has been ...
3
votes
1answer
86 views
PIC18 with ACT HC49/US XTAL
As part of my current project I need to ensure that my MCU (namely PIC18F4520) runs smoothly, minimizing the possibility of any interruptions. The datasheet ...
2
votes
1answer
255 views
Incorrect frequency from crystal oscillator
I acquired an old Eistar SJ-1 Digital pulser. However the frequency it
generates is always 66% of what its supposed to produce. Turns out that
the frequency coming out of the frequency stage(at Pin ...
4
votes
3answers
123 views
Basic electronic watch
I'm thinking about building a simple electronic watch in my spare time.
Not a lot of functions, no LCD, just keeping time and displaying the time using LEDs.
However, I have never created a ...
7
votes
2answers
155 views
Can vibrations of quite an appreciable amplitude affect the clock signal of a crystal oscillator?
I'm very curious to know as I was told that these crystals are electro-mechanical transducers. So theoretically any excess mechanical vibration should result in an error, right?
5
votes
2answers
242 views
How is this crystal / ferrite bead / ground shield connected?
This is part of the schematic for a TI TAS1020B USB Streaming Controller MCU that I don't quite understand. Obviously the shield connects to one end of the ferrite bead, but what else? Are the XTAL ...
1
vote
1answer
279 views
PCB design of crystal/oscillator ok in this way?
I'm working on a 4-Layer PCB design for my quadrocopter. I'm using a STM32F407 and I need the 32 khz and 8 Mhz crystal.
Is the pcb design of my crystal OK?
My layer order:
Sig1
VDD
VSS
Sig2
...
0
votes
2answers
815 views
How to connect a crystal oscillator to generate Square wave
I've a 1 MHZ crystal oscillator.
I want to generate a Square wave of 1 MHZ using the crystal oscillator.
How to connect it and what are the needed components?
1
vote
2answers
133 views
Ground copper pour for Crystals and Real time clocks
I am laying out a (2-layer) board, with a standard SMD Crystal as well as a Real-time clock placed on the top-side of the board.
What are guidelines regarding ground copper pour under the Crystal and ...
2
votes
6answers
364 views
Precise timing with a PIC18 microcontroller?
I'm trying to write a software serial implementation and am having trouble with timing. I'm using Timer0 on a PIC18F242 and for some reason it does not seem to be very accurate.
I've been trying to ...
0
votes
2answers
203 views
HEF4060B counter doesn't count
I'm building (on a breadboard) a 16Mhz oscillator (part of another circuit) with the HEF4060B using an external xtal.
Schematic I'm using is
that's not so different from the example on the ...
2
votes
2answers
293 views
Is case grounding compulsory in typical 32.768kHz crystal for Real Time Clock?
Pictures shown below is a typical 32.768kHz crystal, commonly use in Real Time Clock circuit (e.g: DS1307 & DS1337)
Referring to an earlier question posted here, it is a good practice that ...
6
votes
1answer
358 views
How is my crystal layout looking?
I've done a preliminary layout of my crystals. I've never designed a board with crystals so this is just a rough first pass based on my small set of working knowledge of crystal layout. How am I ...
12
votes
1answer
2k views
Competing PCB Crystal layout recommendations
This is related to this question: How's my crystal oscillator layout?
I'm trying to layout a 12MHz crystal for a micro controller. I've been reading through several recommendations specifically for ...
6
votes
1answer
1k views
Selecting Loading Capacitor Values for 32 kHz Crystal
I need some help selecting loading capacitors for a 32.768 kHz XTAL in a design I'm working on.
This is a bit long, but the big questions are: Is it critical to get the loading cap values right, and ...
5
votes
2answers
159 views
What is the meaning of the nominal frequency specified by manufacturers of crystals?
This answer led to the conclusion that it is unclear what the meaning of the frequency listed by crystal manufacturers actually means.
Given this graph on page 79 of this ECS Crystals Application ...
16
votes
5answers
695 views
What are 12.000393 MHz crystals used for?
I found them on www.digikey.com, and they're apparently made by different manufacturers, so there must be some use for them. What are they used for?
edit
and why? The 2400 baud modem doesn't offer an ...
2
votes
1answer
605 views
Setting up an external clock source on an ATmega8
I am attempting to set up V-USB on my ATmega8-16PU (datasheet), and could use some help hooking up an external crystal clock source to it. I have tried to understand the datasheet to the best of my ...
3
votes
2answers
1k views
Choosing a crystal and load capacitors for micro controller
I'm trying to pick a crystal and load capacitor combination for the atmel UC3C series micro controller. The target CPU clock I'm shooting for is close to the max frequency of 66 MHz.
Here's the ...
1
vote
0answers
59 views
Why is this crystal so tall? [duplicate]
Possible Duplicate:
Does the frequency of a crystal influence its height?
I am looking at s and saw that there are some odd shaped packages. Is there a case where such a tall (13.46mm) ...
1
vote
2answers
1k views
Crystal Oscillator with OP AMP, or Oscillator circuit built with Crystal and Op Amp
I've been trying to make a Oscillator circuit with a Op Amp and an crystal (7.68 MHz)
Similar to the one in the schematic below, but for a 7.68 MHz crystal.
Is this possible? (it says low freq ...
4
votes
1answer
522 views
Using 22pF load caps with 16MHz crystal on atmega328p fails to work
I'm having a hard time figuring out why after attaching 22pF load caps to a 16 Mhz crystal on atmega328p my whole project (aka flashing leds) does not work. Once i remove the load caps everything ...
9
votes
3answers
1k views
Crystals, Oscillators, and Resonators. What the difference?
I am trying to figure out the difference between crystals, oscillators, and resonators. I'm starting to grasp it but I still have some questions.
From my understanding, an oscillator is built from a ...
2
votes
2answers
419 views
Making a suitable antenna for a crystal radio
I'm trying to build a simple AM crystal radio, however, I'm not getting any voltage registered when using it. This is the kind that's only powered by the radio waves. The site I was using to design it ...
6
votes
3answers
1k views
How do I use a quartz crystal in an oscillator?
How can I get a quartz crystal to make square waves at 4.096MHz? So far I have the 4.096MHz quartz crystal and this schematic I saw:
Where can you find an amplifier with a single input and what ...
3
votes
3answers
204 views
Isolation of watch crystal from ICSP
I'm working on a project which uses a PIC with a 32kHz watch crystal attached to Timer1. Unfortunately, the chip I'm currently using, PIC16F1827, shares the T1OSI & T1OSO pins with ICSPCLK & ...
14
votes
1answer
1k views
Why do Arduinos ship w/ 16MHz crystal instead of 20MHz?
Why do Arduino boards ship w/ 16MHz crystal instead of 20MHz? They are spec'ed for operating at 20MHz, after all.
I guess there are a few advantages to running more slowly (lower power consumption, ...
1
vote
1answer
235 views
Broken 32kHz Oscillator
I am trying to build a simple 32kHz crystal oscillator but I am seeing something strange. I am using a simple circuit in that the crystal is in feedback around a current starved inverter.
However, I ...
3
votes
1answer
164 views
Is using a shorter timer period less accurate than using a longer one?
I'm using a dsPIC 33FJ128GP804 and I'm trying to record data at 200 Hz as accurately as possible. My device also has a GPS and I'm noticing that my timer is drifting compared to the GPS by about 333 ...
3
votes
2answers
265 views
Synchronise crystal oscillator with external short burst
I am trying to generate a stable 4.43361875 MHz clock (i.e. PAL colourburst) synchronised to the colourburst of a PAL video signal.
In a PAL signal the colourburst is provided for only about 8-10 ...
7
votes
3answers
1k views
How do you Calibrate 32.768kHz crystal for PIC24 RTCC
I'm trying to figure out the best method for PIC24 RTCC crystal calibration.
Their application note states two methods: using a lookup table and using a reference system clock.
According to them the ...
4
votes
6answers
1k views
PIC keeps resetting: Am I seeing side-effects from breadboard use?
I'm using PIC18F4680 and am having problems running it form a 40 MHz external clock source or 10 MHz crystal in HSPLL mode. Using 10 MHz crystal in HS mode seems to be fine and 5 MHz crystal in HSPLL ...
-2
votes
4answers
590 views
Generation of clock signals
Inside a computer, a crystal oscillator sends signals to a microcontroller or microprocessors. I want to know if the crystal oscillator is increasing the frequency or generating pulses. My questions ...
1
vote
1answer
440 views
Timer1 not running on PIC16F628
I have this little project that requires exact clock so I'm using 32768 Hz quartz on RB6 & RB7 on my PIC16F628. Both pins are grounded using 33 pF capacitors.
My code that configures the timer1 ...
10
votes
1answer
331 views
How close do I really have to place a 25MHz crystal?
I'm laying out a very space constrained PCB. Normally I would place a 25MHz crystal absolutely as close as possible to the chip using it. However, on this PCB, something else really needs the space ...
0
votes
2answers
279 views
Vanilla crystals stability
I wonder which of commonly used crystals in PC have higher short- and long-term stability, in stable temperature & voltage environment?
Crystals I commonly see there are:
32kHz watch crystals ...
1
vote
2answers
768 views
Digital Clock Circuit
I am making a solid wood clock using minimal components. So far, I thought of using 21 LEDs to make 7 segment displays (3 LEDs for each segment (overall 63 LEDs for the displays)), 6 LEDs for the 1 in ...
7
votes
1answer
666 views
My 12 MHz crystal does not oscillate
I am having trouble with a board I have had fabricated. The processor is an NXP LPC1788 Cortex-M3.
I am using a 12 MHz external crystal to clock the processor as recommended in the datasheet.
...
2
votes
2answers
198 views
What loading capacitor do I use for my crystal?
I am using this crystal (the 7.3728 MHz variant).
The datasheet specifies a 5pF to 55pF load capacitance; is this really so? I was under the impression that most quartz crystals had an optimal ...
