how is 20mhz is different from 20mhz resonator?

Vladimir

How is 20 Mhz resonator (http://www.parallax.com/detail.asp?product_id=250-02060) is different from

20 mhz crystal (http://www.allelectronics.com/cgi-bin/item/CY-20/197/20_MHZ_CRYSTAL_.html)?


thanks a lot, im trying to make a homebrew basic stamp based on (http://www.weethet.nl/english/basicstamp2_homebrew.php) site. please help..

thanks again

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Thanks,

Vladimir
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Newzed

With a crystal you have to add the two caps.· With a resonator, the caps are contained in the resonator chip.

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Sid Weaver
Do you have a Stamp Tester yet?
http://hometown.aol.com/newzed/index.html

·

PJAllen

You wouldn't be the first person to take a stab at this weethet circuit, but I haven't·read of·anyone have anything but trouble with it.

Bamse

The BASIC Stamp 2 OEM Module kit is still on sale for $30...

http://www.parallax.com/detail.asp?product_id=27291

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

allanlane5

An oscillator oscillates at a particular frequency because it contains a device that has a 'resonant frequency'. The 'Q' of that device is how 'steep' (or narrow) is that device's response. Another important aspect is how that frequency varies with temperature.

The crystal in a crystal oscillator is a piece of quartz. It has a very high 'Q', and can be tuned by the manufacturer to produce a very accurate oscillator at a particular frequency. It's reasonably stable over temperature.

A resonator does not have a crystal inside it. It's accuracy is not nearly as high as a crystal oscillator. But since it's so much cheaper, it's often used in applications where being .0001% accurate is not that important. I believe it also takes less power.

More expensive (and more accurate) oscillators use a piece of quartz inside a little 'heater', which maintains the crystal at an even temperature. This takes more power, of course.