Faster Instrument Amps?

[Chris Carlen]

Hi:

My jellybeam instrument amp is LT1167. It has a full power bandwidth of
about 12kHz with +-15V supplies, despite a small signal bandwidth of
1MHz @ G=1.

I need an instrument amp that is stable for G=1 and with full power
bandwidth of >=120kHz, putting +-10V into a >=2k load. So that's at
least a 7.5V/us slew rate. Also need input voltage range to be to
within 2V of the supplies, which should be able to go to at least +-15V.
Oh, and typical high-Z inputs, at least 1Mohm CM and 1Mohm differential.

LT has the LT1102, which would be great if it could work with a gain of
unity.

Any fast instrument amps that you know of off the cuff before I kill a
day trying to find such a beast?


Thanks for input.


Good day!


--
_______________________________________________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarle@sandia.gov -- NOTE: Remove "BOGUS" from email address to reply.

 

[John Larkin]

On Thu, 03 Feb 2005 14:07:06 -0800, Chris Carlen
<crcarle@BOGUS.sandia.gov> wrote:

Hi:

My jellybeam instrument amp is LT1167. It has a full power bandwidth of
about 12kHz with +-15V supplies, despite a small signal bandwidth of
1MHz @ G=1.

I need an instrument amp that is stable for G=1 and with full power
bandwidth of >=120kHz, putting +-10V into a >=2k load. So that's at
least a 7.5V/us slew rate. Also need input voltage range to be to
within 2V of the supplies, which should be able to go to at least +-15V.
Oh, and typical high-Z inputs, at least 1Mohm CM and 1Mohm differential.

LT has the LT1102, which would be great if it could work with a gain of
unity.

Any fast instrument amps that you know of off the cuff before I kill a
day trying to find such a beast?


Thanks for input.


Good day!

Try AD8130 maybe. It's screaming fast, but I didn't check it against
all your requirements. Works for us.

John

 

[Chris Carlen]

John Larkin wrote:

Try AD8130 maybe. It's screaming fast, but I didn't check it against
all your requirements. Works for us.

John

Very close. But differential input range with +-12V supply is only +-2.5V.

So to realize it's output swing capabilities, it has to have G>1.

Thanks for the input.


Good day!



--
_______________________________________________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarle@sandia.gov -- NOTE: Remove "BOGUS" from email address to reply.

 

[Tim Shoppa]

What's your error budget (offset, nonlinearity, gain error, CMRR, ?)
If it doesn't matter much you can roll your own with three (fast and/or
precision and/or low-offset voltage and/or low-offset current) op amps
and a handful of resistors.

But I doubt your error budget is completely inconsequential. If it
were you wouldn't be using an instrumentation amp to begin with...

Tim.