clc440 National Semiconductor Corporation, clc440 Datasheet - Page 4

• Manufacturer Part Number: clc440
• Description: High-speed, Low-power, Voltage Feedback Op Amp
• Manufacturer: National Semiconductor Corporation

General Design Equations
The CLC440 is a unity gain stable voltage feedback
amplifier. The matched input bias currents track well over
temperature. This allows the DC offset to be minimized
by matching the impedance seen by both inputs.
Gain
The non-inverting and inverting gain equations for the
CLC440 are as follows:
Gain Bandwidth Product
The CLC440 is a voltage feedback amplifier, whose
closed-loop bandwidth is approximately equal to the
gain-bandwidth product (GBP) divided by the gain (Av).
For gains greater than 5, Av sets the closed-loop band-
width of the CLC440.
For gains less than 5, refer to the frequency response
plots to determine maximum bandwidth.
http://www.national.com
CLC440 Typical Performance Characteristics
-1.0
-2.0
2.0
-0.1
-0.2
1.0
0.2
0.1
0
0
Pulse Response
Short Term Settling Time
0
Non-inverting Gain:
Inverting Gain:
Closed Loop Bandwidth =
GBP = 230MHz
A
v
20
R
f
Time (5ns/div)
R
A
A
g
40
Time (ns)
V
R
V
= +2
= -2
g
60
R
R
g
f
1
80
R
R
g
f
100
GBP
A
APPLICATION INFORMATION
v
-0.4
-0.8
-1.2
-1.6
-0.1
-0.2
0.4
0.2
0.1
0
0
10
-60
Typical DC Errors vs. Temperature
Long Term Settling Time
-9
10
V
-8
l
os
l
b
io
-20
10
-7
Temperature (C )
10
-6
20
Time (s)
10
-5
10
4
-4
60
(A
10
Output Drive and Settling Time Performance
The CLC440 has large output current capability. The
90mA of output current makes the CLC440 an excellent
choice for applications such as:
When driving a capacitive load or coaxial cable, include a
series resistance R s to back match or improve settling
time. Refer to the “Settling Time vs. Capacitive Load” plot
in the typical performance section to determine the
recommended resistance for various capacitive loads.
When driving resistive loads of under 500 , settling time
performance diminishes. This degradation occurs
because a small change in voltage on the output causes
a large change of current in the power supplies. This
current creates ringing on the power supplies. A small
resistor will dampen this effect if placed in series with the
6.8 F bypass capacitor.
Noise Figure
Noise Figure (NF) is a measure of noise degradation
caused by an amplifier.
where,
NF 10LOG
-3
V
10
= +2, R
100
-2
•
•
10
Video Line Drivers
Distribution Amplifiers
e
e
-1
ni
t
140
10
f
= Thermal Voltage Noise (
= Total Equivalent Input Noise Density
= 250 :V
0
-2
-10
6
2
-6
-14
Due to the Amplifier
S /N
S /N
o
-10
-20
i
20
10
80
60
40
20
0
0
cc
-4.0
I
0.05% Settling Time vs. Capacitive Load
10
b
i
o
= + 5V, R
and I
R
T
s
s
Common-Mode Input Voltage (V)
+
-
-2.4
10LOG
os
Load Capacitance C
vs. Common-Mode Voltage
R
s
L
= 100 unless specified)
C
-0.8
L
1k
100
e
e
ni
t
0.8
2
2
l
4kTR
I
os
b
L
(pF)
2.4
seq
)
1000
4.0
2.0
1.0
-1.0
-2.0
55
45
35
25
15
0