Datasheet
®
OPA2111 12
FIGURE 12. ‘N’ Stage Parallel-Input Amplifier.
7
5
Output
Input
6
10kΩ
1/2OPA2111
10kΩ100Ω
1
3
2
10kΩ
1/2OPA2111
10kΩ100Ω
7
5
6
10kΩ
1/2OPA2111
10kΩ100Ω
1
3
2
10kΩ
1/2OPA2111
10kΩ100Ω
7
5
6
100Ω
1
3
2
10kΩ
1/2OPA2111
10kΩ100Ω
6
3
2
OPA37
1/2OPA2111
10kΩ
N = 10
5 each OPA2111BM
Since signal voltage sums directly with N
but amplifier noise voltage sums as N,
signal-to-noise ratio improves by N.
A
V
= –1010
e
n
= 1.9nV/ Hz typ
(1)
at 10kHz
BW = 30kHz typ
GBW = 30.3 MHz typ
V
OS
= ±16µV typ
(1)
∆V
OS
/∆T = ±0.16µV/°C typ
(1)
I
B
= 40pA max
Z
IN
= 10
12
Ω || 30pF
NOTE: (1) Theoretical performance
achievable from OPA2111BM
with uncorrelated random
distribution of parameters.