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I2C/SPI IC frequency counter

I2C/SPI IC frequency counter

I2C/SPI IC frequency counter

(OP)
I need a frequency counter that can operated from about 10mhz-300mhz, and I'd prefer it be an IC that supports a standard kind of 2 or 4 wire communication - I'd basically like it to operate as if it were an ADC. I tried googling and looking up stuff couldn't really find a part that fits the bill, anyone know of any?

Thanks,
Ambert

RE: I2C/SPI IC frequency counter

Not I, not at 300MHz.  You will probably need to roll your own with an FPGA.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: I2C/SPI IC frequency counter

Hiya-

A PECL prescaller ought to work up to 300MHz (of course
you will loose some resolution).   

I've driven the fast counters in PICs up to 15MHz without
a problem when the pic is run at 20MHz.  After that you
can certianly pass it to I2C interface.

I built a little 100MHz counter with a Fast Schottky
prescaler that was autoranging and drove 8 LEDs. Passed
it to a 16F628 runnning at 20MHz.  Had to adjust the
gate timing to account for the Xtal.  It was interesting
to watch the readout change when I heated up the Xtal
with my finger.......

I used the EEPROM registers to hold the adjustment. Little
bit of a "user interface" to calibrate it.

Should have put an TXCO on it, but it is usually used
around room temperature, so it works o.k.

RE: I2C/SPI IC frequency counter

What kind of accuracy,resolution do you need? Do you have
any FPGA development system?

Any other specs you can add? Every omitted spec adds
to the complexity, design time etc.


Plesae read FAQ240-1032
My WEB: <http://geocities.com/nbucska/>

RE: I2C/SPI IC frequency counter

(OP)
I need resolution to be within 1 Mhz but preferably .5 Mhz.

No real other specs... it's for a test automation setup not production board. Thanks for the information nbucska!

Actually a coworker told me to try Maxim, I'm giving one of their app engineers a call.

RE: I2C/SPI IC frequency counter

(OP)
o, yes I have access to several FPGA development systems, but again I don't really want to spend a lot of effort. I've got a benchtop counter that already has rs232 and GPIB so I am using that now, I just think an IC solution would be that much more slick.

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