rsd@sei.cmu.edu (Richard S D'Ippolito) (05/28/88)
In article <1196@neoucom.UUCP> Bill Mayhew writes:
An integrated operational amplifier that would probaly perform
quite well for audio (hifi?) applications might be the Analog
devices AD318K. This chip can be characterised as a wideband, low
drift, FET input opamp.
Here is a synopsis of its characteristics:
open loop gain: 100,000
output: +/-12v (+/-10 min) at Rl=1K
20 mA short circuit output current limit
dynamic:
unity gian, ss 5 MHz
full power bw 500 KHz
slew rate 30v/uS
.1% settle 700 nS
.01% 1.2 uS
input bias current: 10pA avg, 50 pA max
imput impedances:
differential 1E12 ohms in parallel with 7 pF
common mode 1E12 ohms in parallel with 7 pF
input volrate range:
differential +/- 20 v (maximum safe limit)
common mode +/- 12 v (+/-10 min)
CMR 80 dB minimum
noise figures:
0.1 - 10KHz 2 uV peak-peak
10 Hz 70 nV/Hz^.5
100 Hz 45 nV/Hz^.5
1 KHz 30 nV/Hz^.5
10 KHz 25 nV/Hz^.5
case style: TO-99
Why not make your own? After all, a hundred bucks is a small price to pay
for perfection! (Seriously, these make good QUIET mike preamps.)
The JE-990 discrete op amp(*)
Open loop gain 125 dB
Gain error @ 100-dB gain 0.4 dB
Noise voltage spectral dens. 1.13nV/root Hz
Equiv input noise voltage,
20Khz bandwidth, shorted input 160nV
Noise index, 1000 ohm source 0.6dB
THD @ 20KHz, at 12.3V output
(+24dB)
Load = 75 ohms, gain = 40dB 0.06%
Load = 75 ohms, gain = 20dB 0.005%
Load = 600 ohms, gain = 40dB 0.015%
Unity gain small sig bandwidth 10MHz
Large signal bandwidth
Load = 150 ohms 145Khz
Supply voltage +/- 24V
(*) Parts list and full description is in the Journal of the Audio
Engineering Society, Vol 28, No. 1/2, Jan/Feb 1980. The article is entitled
"JE-990 Discrete Operational Amplifier" by Deane Jensen of Jensen
Transformers. You can buy them already assembled.
Rich