TL441CN Datasheet, PDF (12/20 Pages) Texas Instruments – LOGARITHMIC AMPLIFIER

TL441
LOGARITHMIC AMPLIFIER
SLVS328 – OCTOBER 2000
APPLICATION INFORMATION
TRANSFER CHARACTERISTICS
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
10 ^{– 4} 10 ^–3 10 ^–2 10 ^–1
1
101
Input Voltage – V
1 kΩ
910 Ω
Input
100 Ω
VCC ₊ = 4 V
+
15 kΩ
–
VCC _– = – 4 V
5 kΩ
1 kΩ
910 Ω
VCC ₊ = 4 V
+
–
VCC _– = – 4 V
A1
Y
A2
Y
TL441
B1
Z
B2
Z
2 kΩ
Origin
20 kΩ
2 kΩ
2 kΩ
+
–
Slope
5 kΩ
Output
100 Ω
5 kΩ
NOTES: A. Inputs are limited by reducing the supply voltages for the input amplifiers to ± 4 V.
B. The gains of the input amplifiers are adjusted to achieve smooth transitions.
Figure 15. Logarithmic Amplifier With Input Voltage Range Greater Than 80 dB
12
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