Datasheet

TL441
LOGARITHMIC AMPLIFIER
SLVS328 – OCTOBER 2000
14
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
2 kΩ 2 kΩ
Origin
20 kΩ
2 kΩ
2 kΩ
Slope
A1
A2
Y
Y
1/2
TL441
Input
A
Output
W
+
–
–
+
NOTE: Adjust the slope to correspond to the base “a”.
Exponential to any base: W = a.
Figure 18. Raising a Fixed Number to a Variable Power
+
–
20 kΩ
20 kΩ
Input
1
2.2 kΩ
0.2 µF
Output
1
Input
2
Output
2
TL592
TL592
0.2 µF
1 kΩ 1 kΩ
Gain Adj.
2.2 kΩ
2.2 kΩ
2.2 kΩ
0.2 µF
0.2 µF
1 kΩ 1 kΩ
0.2 µF
Gain Adj. = 400 Ω
For 30 dB
Gain Adj. = 400 Ω
For 30 dB
0.2 µF
TL592
TL592
50 Ω
50 Ω 50 Ω
Open
Open
C
A2
C
A2’
Y
Y
Z
Z
C
B2
C
B2’
A1
A2
B1
B2
TL441
10
kΩ
10
kΩ
V
CC –
Gain Adj.
+
–
+
–
+
–
50 Ω
+
–
+
–
Figure 19. Dual-Channel RF Logarithmic Amplifier With 50-dB Input Range Per Channel at 10 MHz