5-10 MHz Clock Generation

[CommonSorcerer]

I need to generate a clock. I could do this using a PLL, but from the ADI or TI chips I've seen, they're typically large (lots of pins) and consume upwards of 100mW of power. (sorry, I'm new to this stuff)

Does anyone have a suggestion of what chip I can use to get this clock? I need 2 outputs, 180 degrees apart ranging from 5-10MHz with a resolution of 10KHz with a 'high' voltage of at least 5V. I would prefer having a chip with minimal output pins, as I need to make this very compact. Phase noise isn't really an issue in my design.

Previously, I had been using an ADI chip that sets the frequency using an RC time constant, but the output was very unstable and had trouble "locking" into the desired frequency.

Thank you ahead of time.

-Michael

 

[barry]

How are you going to control the frequency? With a pot? With a digital command? You could use a small FPGA/CPLD to do this. There are lots of small plls, (they might have lots of pins, but they're small).

 

[schmitt trigger]

Go to the Linear Tech website, and search the "TimerBlox" series of silicon oscillators. They have exactly what you require.

 

[CommonSorcerer]

Ideally, I would control it with something as simple as a potentiometer, but from my experience using the LTC6902, there's a lot of jitter, and I believe using SPI or I2C from a microprocessor would be more suitable for my application. I'm currently considering the LTC6903 or 6904 for the simplicity.

 

[KlausST]

Hi,

If you want to adjust frequency with a pot, then I assume you need no "locked" frequency stability.

A VCO could work. An an inverter as 180° source.

Klaus