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6
±5V Typical Channel Matching Performance
(A
v
= +2, R
f
= 750
, R
L
= 100
,V
CC
= ±5V, unless specified)
Channel Matching
M
Frequency (Hz)
1M
10M
100M
Channel 1
Channel 2
Input Referred Crosstalk
M
Frequency (Hz)
1M
10M
100M
-90
-80
-70
-60
-50
-40
-20
-30
V
o
= 1V
pp
Pulse Crosstalk
A
A
Time (10ns/div)
I
A
Active Output
Channel
Inactive Output
Channel
CLC5622 OPERATION
The CLC5622 is a current feedback amplifier built in an
advanced complementary bipolar process. The CLC5622
operates from a single 5V supply or dual ±5V supplies.
Operating from a single supply, the CLC5622 has the
following features:
I
Provides 100mA of output current while
consuming 15mW of power
I
Offers low -80/-83dB 2nd and 3rd harmonic
distortion
I
Provides BW > 80MHz and 1MHz distortion
< -75dBc at V
o
= 2V
pp
The CLC5622 performance is further enhanced in ±5V
supply applications as indicated in the
±5V Electrical
Characteristics
table and
±5V Typical Performance
plots.
Current Feedback Amplifiers
Some of the key features of current feedback technology
are:
I
Independence of AC bandwidth and voltage gain
I
Inherently stable at unity gain
I
Adjustable frequency response with feedback resistor
I
High slew rate
I
Fast settling
Current feedback operation can be described using a simple
equation. The voltage gain for a non-inverting or inverting
current feedback amplifier is approximated by Equation 1.
Equation 1
where:
I
A
v
is the closed loop DC voltage gain
I
R
f
is the feedback resistor
I
Z(j
ω
) is the CLC5622’s open loop
transimpedance gain
ω
( )
I
is the loop gain
The denominator of Equation 1 is approximately equal to
1 at low frequencies. Near the -3dB corner frequency, the
interaction between R
f
and Z(j
ω
) dominates the circuit
performance. The value of the feedback resistor has a
large affect on the circuits performance. Increasing R
f
has the following affects:
I
Decreases loop gain
I
Decreases bandwidth
I
Reduces gain peaking
I
Lowers pulse response overshoot
I
Affects frequency response phase linearity
Refer to the
Feedback Resistor Selection
section for
more details on selecting a feedback resistor value.
V
V
A
1
R
Z(j )
o
in
v
f
=
+
Z j
R
f
CLC5622 DESIGN INFORMATION
Single Supply Operation (V
CC
= +5V,V
EE
= GND)
The specifications given in the
+5V Electrical Character-
istics
table for single supply operation are measured with
a common mode voltage (V
cm
) of 2.5V. V
cm
is the volt-
age around which the inputs are applied and the
output voltages are specified.
Operating from a single +5V supply, the Common Mode
Input Range (CMIR) of the CLC5622 is typically +0.8V to
+4.2V. The typical output range with R
L
=100
is +1.0V
to +4.0V.
For single supply DC coupled operation, keep input
signal levels above 0.8V DC. For input signals that drop
below 0.8V DC, AC coupling and level shifting the signal
are recommended. The non-inverting and inverting
configurations for both input conditions are illustrated in
the following 2 sections.