[sdiy] Phase reversal-free op amp

[Andre Majorel]

On 2011-02-15 23:10 +0000, Neil Johnson wrote:

> >Do you folks have any recommendations for phase reversal-free,
> >high input impedance op amps ?
> 
> How about OPA132?
> 
> I keep a little page just for this very question:
> 
> http://www.milton.arachsys.com/nj71/index.php?
> menu=2&submenu=2&subsubmenu=2

Thanks Neil, nice page. Here's what I've found :

OPA132/OPA2132/OPA4132
  Limited CM input range, limited output swing.

OPA134
  Limited CM input range, limited output swing, not very precise.

OPA141/OPA2141/OPA4141:
  Limited CM input range, 1 mV typ, 3.5 mV max.

LM324
  Limited CM input range, limited output swing, not really
  high-Z and not very precise. And, to top it all, slower than
  the OPA2277. So thanks Tim, but no thanks. <g>

LT1055/LT1056
  Limited CM input range, limited output swing.

LT1498/LT1499
  Not high-Z (650 nA).

LT1630/LT1631
  Not high-Z (1 µA).

LT1632/LT1633
  Not high-Z (2 µA), not very precise.

LT1677/LT1678/LT1679
  Not very high-Z (20 nA)

Seems the best candidate so far is the LT1677/LT1678/LT1679.
It's not terribly cheap, though. The search continues...

-- 
André Majorel http://www.teaser.fr/~amajorel/