From: Winfield Hill
Subject: Re: accurate fast opamps
Date: 14 Nov 2002 06:17:14 -0800
Organization: Rowland Institute
X-Newsreader: Direct Read News 4.10
>Winfield Hill wrote:
>> Winfield Hill wrote...
>>> Let's talk about our favorite fast accurate opamp, in this case
>>> I'm calling out f_T faster than 5 MHz, Vos under 150uV typical
>>> (bipolar, right?), Ibias < 20nA. Oh, and operating from 12.5V
>>> total supply. :-) Is your favorite choice up to the task?
>> Bill Sloman wrote me pointing out the joys of the 20-year-old
>> LT1007 and LT1037 opamps, or even the venerable OP-27 and OP-37
>> chips. These parts would indeed appear to fill my need, if I
>> can trust their 30V supply specs to be trustworthy at 10V total
>> supply voltage. The older OP-27 data sheet says very little
>> about operation below +/-15V, not giving me much guidance. But
>> the LT1007 has curves showing specs down to below +/-3V supply,
>> including constant Ig curves, which inspires confidence. They
>> also have output drive capability shown as a voltage difference
>> from the supply rails, very important data.
>> But sadly, I left out an important parameter for me, this must
>> be a dual opamp. I'd like a dual miniDIP LT1007... Ah, Linear
>> Technology's LT1124 looks good.
>> Good call Bill. :-)
> the 1124 is a very nice amp, but the pinout of the SO-8 package is
> weird; I think the die must be big, so is rotated in the package.
> If you use it, be careful.
> OP-227 is nice, basicly a dual OP-27. Some of the older parts are
> handy because they are multi-sourced and cheap.
Thanks, John. I was hoping to elicite some newer parts, designed
for use with lower supply voltages. Few legacy parts are spec'd
or tested with +/-5V supplies, even if they may work well at low
voltages, so it would make sense to choose a more modern part.