Datasheet

TL441
LOGARITHMIC AMPLIFIER
SLVS328 – OCTOBER 2000
9
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
output levels
Differential-output-voltage levels are low, generally less than 0.6 V. As demonstrated in Figure 12, the output
swing and the slope of the output response can be adjusted by varying the gain by means of the slope control.
The coordinate origin also can be adjusted by positioning the offset of the output buffer.
circuits
Figures 12 through 19 show typical circuits using this logarithmic amplifier. Operational amplifiers not otherwise
designated are TLC271. For operation at higher frequencies, the TL592 is recommended instead of the
TLC271.
Output Voltage – V
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
– 0.2
10
– 4
10
–3
10
–2
10
–1
10
1
1
TYPICAL TRANSFER
CHARACTERISTICS
Adjusted for Increased
Slope and Offset
Adjusted For Minimum
Slope With Zero Offset
Input Voltage – V
Input
A1
A2
Y
Y
1/2
TL441
Origin
Slope
Output
GND
+
–
+
–
Figure 12. Output Slope and Origin Adjustment