clc5612 National Semiconductor Corporation, clc5612 Datasheet - Page 11

• Manufacturer Part Number: clc5612
• Description: Dual, High Output, Programmable Gain Buffer
• Manufacturer: National Semiconductor Corporation

Typical Performance Characteristics
V
Pulse Crosstalk
Application Division
CLC5612 Operation
The CLC5612 is a current feedback buffer fabricated in an
advanced complementary bipolar process. The CLC5612
operates from a single 5V supply or dual
Operating from a single 5V supply, the CLC5612 has the
following features:
The CLC5612 performance is further enhanced in
supply applications as indicated in the
Characteristics table and
If gains other than +1, −1, or +2V/V are required, then the
CLC5602 can be used. The CLC5602 is a current feedback
amplifier with near identical performance and allows for
external feedback and gain setting resistors.
Current Feedback Amplifiers
Some of the key features of current feedback technology
are:
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.
where:
• Gains of +1, −1, and 2V/V are achievable without
•
• Offers low −79/−81dBc 2nd and 3rd harmonic distortion
• Provides BW
• Independence of AC bandwidth and voltage gain
• Inherently stable at unity gain
• Adjustable frequency response with feedback resistor
• High slew rate
• Fast settling
• A
• R
CM
external resistors
7.5mW of power
V
, unless specified) (Continued)
Provides 100mA of output current while consuming only
O
V
f
is the feedback resistor
is the closed loop DC voltage gain
= 2V
PP
Active Output
Channel
>
50MHz and 1MHz distortion
V
V
in
o
Time (10ns/div)
1
±
5V Typical Performance plots.
A
Z(j )
R
v
f
Inactive Output
Channel
±
±
5V Electrical
5V supplies.
<
DS015001-36
−75dBc at
±
5V
(1)
(A
11
V
= +2, R
The denominator of Equation 1 is approximately equal to 1 at
low frequencies. Near the −3dB corner frequency in the
interaction between R
performance. The value of the feedback resistor has a large
affect on the circuits performance. Increasing R
following affects:
CLC5612 Design Information
Closed Loop Gain Selection
The CLC5612 is a current feedback op amp with R
on chip (in the package). Select from three closed loop gains
without using any external gain or feedback resistors.
Implement gains of +2, +1, and −1V/V by connecting pins 2
and 3 (or 5 and 6) as described in the chart below.
The gain accuracy of the CLC5612 is excellent and stable
over temperature change. The internal gain setting resistors,
R
variation of
−2000ppm/˚C. Although their absolute values change with
processing and temperature, their ratio (R
constant. If an external resistor is used in series with R
accuracy over temperature will suffer.
Single Supply Operation (V
The
Characteristics table for single supply operation are
measured with a common mode voltage (V
the voltage around which the inputs are applied and the
output voltages are specified.
• Z(j ) is the CLC5612’s open loop transimpedance gain
• Z(j )/R
• Decreases loop gain
• Decreases bandwidth
• Reduces gain peaking
•
• Affects frequency response phase linearity
Gain A
−1V/V
+1V/V
+2V/V
f
and R
Lowers pulse response overshoot
specifications
L
= 100 , V
V
g
f
is the loop gain
are diffused silicon resistors with a process
Input Connections
Non-Inverting (pins 3,5)
ground
input signal
input signal
±
20% and a temperature coefficient of
S
+5V
given
f
1
, V
and Z(j ) dominates the circuit
CM
cc
in
= +5V/V, V
= V
EE
the
+(V
Inverting (pins 2,6)
input signal
NC (open)
ground
S
cm
±
/2), R
EE
5V
) of 2.5V. V
=GND)
f
/R
www.national.com
g
L
) remains
Electrical
f
f
=R
tied to
has the
g
g
=1k
, gain
cm
is