(A = +2, R = 1kΩ (PDIP), R = 100Ω, VCC = ±5V, unless specified)
±5V Typical Channel Matching Performance
v
f
L
Pulse Crosstalk
Channel Matching
Input Referred Crosstalk
-20
-35
-45
-55
-65
-75
PDIP Package
Vo = 1Vpp
Active Output
Channel
Channel 3
Channel 2
Inactive Output
Channel 2
Inactive Output
Channel 3
Channel 1
Active Output
Channel 1
Time (20ns/div)
1M
10M
100M
1M
10M
100M
Frequency (Hz)
Frequency (Hz)
CLC5623 OPERATION
The CLC5623 is a current feedback amplifier built in an
advanced complementary bipolar process. The CLC5623
operates from a single 5V supply or dual ±5V supplies.
Operating from a single supply, the CLC5623 has the
following features:
V
A
o
v
R
=
Equation 1
V
f
in
1+
Z(jω)
where:
■
■
■
A is the closed loop DC voltage gain
v
■
Provides 100mA of output current while
consuming 15mW of power
Offers low -85/-96dB 2nd and 3rd harmonic
R is the feedback resistor
f
■
Z(jω) is the CLC5623’s open loop
distortion
transimpedance gain
■
Provides BW > 100MHz and 1MHz distortion
Z jω
(
)
is the loop gain
■
< -70dBc at V = 2V
o
pp
R
f
The CLC5623 performance is further enhanced in ±5V
supply applications as indicated in the ±5V Electrical
Characteristics table and ±5V Typical Performance plots.
The denominator of Equation 1 is approximately equal to
1 at low frequencies. Near the -3dB corner frequency, the
interaction between R and Z(jω) dominates the circuit
f
Current Feedback Amplifiers
performance. The value of the feedback resistor has a
Some of the key features of current feedback technology
are:
large affect on the circuits performance. Increasing R
has the following affects:
f
■
Independence of AC bandwidth and voltage gain
Inherently stable at unity gain
Adjustable frequency response with feedback resistor
High slew rate
■
Decreases loop gain
■
■
Decreases bandwidth
■
■
Reduces gain peaking
■
■
Lowers pulse response overshoot
■
Fast settling
■
Affects frequency response phase linearity
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.
Refer to the Feedback Resistor Selection section for
more details on selecting a feedback resistor value.
CLC5623 DESIGN INFORMATION
Single Supply Operation (V = +5V, V = GND)
+4.2V. The typical output range with R =100Ω is +1.0V
CC
EE
L
The specifications given in the +5V Electrical Character-
istics table for single supply operation are measured with
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.
a common mode voltage (V ) of 2.5V. V is the volt-
cm
cm
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 CLC5623 is typically +0.8V to
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