[sdiy] AD821 (more)

[Paul Perry]

The Word:

from the Prophet known as Barry Klein: (via google)

"The AD821 and AD818 are no more. Even their temporary recommended
replacements from MicroPower (MP310/11/12) are out of production. So what to
use? Well, some circuits have used the CA3046 (NPN) but most builders report
rather poor performance. Check out National Semiconductor's AN-299 and
Linear Technology's LT1055 data sheet for examples design examples. I would
suggest trying the matched transistor arrays from Analog Devices like the
MAT-03 or SSM-2220 (PNP) or the MAT-01, -02, -04, or SSM-2210 parts (NPN). "

best, paul perry melb aust