Datasheet
SLOS214C − OCTOBER 1998 − REVISED MARCH 2007
22
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
output clamping (continued)
−4
−3
−2
−1
0
1
2
3
4
−4−3−2−1012345
OUTPUT VOLTAGE
vs
CLAMP VOLTAGE (V
L
)
Clamp Voltage − V
R
L
=5.1 k Ω
V
O
− Output Voltage − V
V
CC
=±5 V & ±15 V
V
I
=5 V
Gain=+2 dB
R
L
=500 Ω
−4
−3
−2
−1
0
1
2
3
4
−5−4−3−2−101234
OUTPUT VOLTAGE
vs
CLAMP VOLTAGE (V
H
)
Clamp Voltage − V
R
L
=5.1 k Ω
V
O
− Output Voltage − V
V
CC
=±5 V & ±15 V
V
I
=−5 V
Gain=+2 dB
R
L
=500 Ω
Figure 58. Output Voltage vs Clamp Voltage
The accuracy of this clamp is dependant on the amount of current flowing through the internal clamping diodes.
As is typical with all diodes, the voltage drop across this diode increases with current. Therefore, the accuracy
of the clamp is highly dependant upon the output voltage, the clamping voltage difference, and the output
current. The accuracy of the clamps with different load resistances are shown in Figure 59.
−200
−160
−120
−80
−40
0
40
−5 −4 −3 −2 −1 0
V
L
=−4 V
NEGATIVE CLAMP ACCURACY (V
L
)
Expected Output Voltage− V
R
L
=500 Ω
Gain = +2dB
V
L
=−1 V
V
L
=−2 V
V
L
=−3 V
−160
−120
−80
−40
0
40
80
−5 −4 −3 −2 −1 0
V
L
=−4 V
R
L
=1 k Ω
Gain = +2dB
V
L
=−1 V
V
L
=−2 V
V
L
=−3 V
NEGATIVE CLAMP ACCURACY (V
L
)
Expected Output Voltage − V
−160
−120
−80
−40
0
40
80
−5 −4 −3 −2 −1 0
V
L
=−4 V
R
L
=5.1 k Ω
Gain = +2dB
V
L
=−1 V
V
L
=−2 V
V
L
=−3 V
NEGATIVE CLAMP ACCURACY (V
L
)
Expected Output Voltage − V
V
O
− V
CLAMP
V
O
− V
CLAMP
V
O
− V
CLAMP
−80
−40
0
40
80
120
160
012345
V
H
=4 V
R
L
=500 Ω
Gain = +2dB
V
H
=1 V
V
H
=2 V
V
H
=3 V
POSITIVE CLAMP ACCURACY (V
H
)
Expected Output Voltage − V
−120
−80
−40
0
40
80
120
012345
V
H
=4 V
R
L
=1 k Ω
Gain = +2dB
V
H
=1 V
V
H
=2 V
V
H
=3 V
POSITIVE CLAMP ACCURACY (V
H
)
Expected Output Voltage − V
−120
−80
−40
0
40
80
120
012345
V
H
=4 V
R
L
=5.1 k Ω
Gain = +2dB
V
H
=1 V
V
H
=2 V
V
H
=3 V
POSITIVE CLAMP ACCURACY (V
H
)
Expected Output Voltage − V
V
O
− V
CLAMP
V
O
− V
CLAMP
V
O
− V
CLAMP
Figure 59. Clamping Accuracy