[time-nuts] Fury Interface Board: How about TI OPA277?

Bruce Griffiths bruce.griffiths at xtra.co.nz
Fri Nov 2 00:13:13 EDT 2007

David Forbes wrote:
> At 9:09 PM -0600 11/1/07, xaos at darksmile.net wrote:
>> It is funny how things you forgot a long time ago have a way of coming back.
>> Case in point. I was just running some simulations on the EFC
>> interface and then I had this idea.
>> Wouldn't an instrumentation amplifier be the right way the isolate the
>> Fury EFC    voltage?
>> For instance, the Burr Brown INA 103. It would provide for isolation
>> as well as gain. Not sure of all the details yet.
>> I remember using this device for a thermocouple a few years back. And
>> I even managed to find a few of them in a box somewhere.
> The AD620 or LT1167 is a fine little instrumentation amp. 8-pin 
> package. Very easy to use, good specs.
The SSM2143 or equivalent is perhaps a better fit at least for a 10811A.
No external gain setting resistors are required for a 10811A.
An additional opamp or 2 plus an RC filter are necessary for low sense
lead current in the 10811A EFC pin.
However these opamps don't need any gain setting resistors.
Devices like the AMP03 and its equivalents only have unity gain and are
significantly noisier.


More information about the time-nuts mailing list