Datasheet

Electrical Characteristics LM2904
10/15
Figure 20. Non-inverting DC gain Figure 21. DC summing amplifier
Figure 22. High input Z, DC differential
amplifier
Figure 23. Using symmetrical amplifiers to
reduce input current
Figure 24. Low drift peak detector Figure 25. Active bandpass filter
R1
10k
Ω
R2
1M
Ω
1/2
LM2904
10k
Ω
e
I
e
O
+5V
e
O
(V)
(mV)
0
A
V
=1+
R2
R1
(As shown = 101)
A
V
1/2
LM2904
e
O
e
4
e
3
e
2
e
1
100k
Ω
100k
Ω
100k
Ω
100k
Ω
100k
Ω
100k
Ω
eo = e1 + e2 - e3 - e4
where (e1 + e2) (e3 + e4)
to keep eo 0V
≥
≥
+
1/2
LM2904
R1
100k
Ω
R2
100k
Ω
R4
100k
Ω
R3
100k
Ω
+V2
V1
V
o
1/2
LM2904
If R1 = R5 and R3 = R4 = R6 = R7
eo = [ 1 + ] (e2 - e1)
As shown eo = 101 (e2 - e1)
2R1
R2
I
B
2N 929
0.001
µ
F
I
B
3M
Ω
I
B
e
o
I
I
e
I
I
B
I
B
Input current compensation
1.5M
Ω
1/2
LM2904
1/2
LM2904
1/2
LM2904
I
B
2N 929
0.001
µ
F
I
B
3R
3M
Ω
I
B
Input current
compensation
e
o
I
B
e
I
Z
o
Z
I
C
1
µ
F
2I
B
R
1M
Ω
2I
B
1/2
LM2904
1/2
LM2904
1/2
LM2904
R8
100k
Ω
C3
10
µ
F
R7
100k
Ω
R5
470k
Ω
C1
330pF
V
o
V
CC
R6
470k
Ω
C2
330pF
R4
10M
Ω
R1
100k
Ω
R2
100k
Ω
+V1
R3
100k
Ω
1/2
LM2904
1/2
LM2904
Fo = 1kHz
Q = 50
Av = 100 (40dB)