Crystal vs Oscillator Explained?

[skammer]

crystal vs oscillator

I am researching a clock source to be used in a future project and I am little unsure about the difference between a crystal and an oscillator. We are gonna run a uController at 20mhz, and you can find that frequency in both types of clock sources. I see that some oscillators are called crystal oscillators. I understand the basic theory of how these work, but don't understand the differnces between the two. Can anyone help?

Also looking for help on how to make a PLL circuit for a pic micro that can use a PLL to clock up the speeds ...any help appreciated.

 

[echo47]

oscillator vs crystal

A crystal is a chunk of quartz with attached wires. You must provide the external circuitry to make it oscillate.

A crystal oscillator is a crystal and oscillator ciruitry in one convenient package. You simply apply power. These cost more than just a crystal.

Many microcontrollers have built-in oscillator circuity, so all you need is a crystal and maybe a couple capacitors. Most microcontrollers also accept a crystal oscillator signal. Read your microcontroller data sheet for specific instructions.

Tell us your PLL input and output frequencies. Someone here will probably have suggestions.

 

[skammer]

crystal vs crystal oscillator

I would be using a 10mhz base frequncy, with a multiplier of 4.