ha3-2556-9 Intersil Corporation, ha3-2556-9 Datasheet - Page 7

• Manufacturer Part Number: ha3-2556-9
• Description: 57mhz, Wideband, Four Quadrant, Voltage Output Analog Multiplier
• Manufacturer: Intersil Corporation

scaled with the value of R
impedance of typically 1M . The equation for I
Video Fader
The Video Fader circuit provides a unique function. Here Ch B
is applied to the minus Z input in addition to the minus Y input.
In this way, the function in Figure 11 is generated. V
control the percentage of Ch A and Ch B that are mixed
together to produce a resulting video image or other signal.
The Balance equation looks like:
Which simplifies to:
When V
Ch A is removed, conversely when V
becomes V
0V
Other Applications
As shown above, a function may contain several different
operators at the same time and use only one HA-2556.
Some other possible multi-operator functions are shown in
Figures 12, 13 and 14.
I
V
OUT
V
Ch A
Ch B
OUT
A
MIX
B
V
=
=
MIX
MIX
V
V
V
V
A B
------------- -
ChB
V
V
X
X
Y
Y
ChA ChB
5
Y
Y
+
-
+
-
-15V
OUT
+
-
1/5V
is 0V the equation becomes V
NC
NC
NC
5V the output is a blend of Ch A and Ch B.
+
–
+
+
-
-
FIGURE 10. CURRENT OUTPUT
------------------------------- -
R
V
------------- - ChA ChB
= Ch A eliminating Ch B. For V
MIX
CONVERT
5
FIGURE 11. VIDEO FADER
1
2
3
4
5
6
7
8
1
Y
X
=
HA-2556
REF
+
5 V
-
CONVERT
–
50
+
OUT
+
-
-
7
–
Z
+
+
-
-
ChB
and provides an output
16
15
14
13
12
11
10
A
9
MIX
+
-
V
OUT
V
V
V
X
V
V
OUT
Z
is 5V the equation
Z
NC
NC
NC
+15 V
Z
Z
+
+
-
+
-
(0V to 5V)
OUT
R
= Ch B and
V
CONVERT
MIX
MIX
becomes:
MIX
values
V
OUT
will
I
OUT
HA-2556
Of course the HA-2556 is also well suited to standard
multiplier applications such as Automatic Gain Control and
Voltage Controlled Amplifier.
Automatic Gain Control
Figure 15 shows the HA-2556 configured in an Automatic
Gain Control or AGC application. The HA-5127 low noise
amplifier provides the gain control signal to the X input. This
control signal sets the peak output voltage of the multiplier to
match the preset reference level. The feedback network
around the HA-5127 provides a response time adjustment.
High frequency changes in the peak are rejected as noise or
the desired signal to be transmitted. These signals do not
indicate a change in the average peak value and therefore
no gain adjustment is needed. Lower frequency changes in
the peak value are given a gain of -1 for feedback to the
control input. At DC the circuit is an integrator automatically
compensating for Offset and other constant error terms.
FIGURE 14. DIFFERENCE DIVIDED BY SUM S (For A + B 0V)
B
R
For A 0V .
A
1
5K
5K
A
and R
R
5K
5K
5K
1
2
V
V
V
V
V
V
V
V
X
Y
Y
FIGURE 12. DIFFERENCE OF SQUARES
set scale to 1V/%, other scale factors possible.
X
Y
Y
X
V
V
V
V
X
FIGURE 13. PERCENTAGE DEVIATION
+
-
-
+
+
+
-
-
X
X
Y
Y
1/5V
+
-
+
-
1/5V
1/5V
+
+
-
-
+
+
-
-
+
+
95K
-
-
R
2
Y
X
X
Y
Y
X
HA-2556
HA-2556
HA-2556
+
+
-
+
-
-
Z
Z
Z
A
+
A
-
A
+
-
+
-
V
V
V
V
OUT
V
V
OUT
Z
Z
Z
Z
V
V
+
-
+
-
Z
Z
+
-
W = 100
W = 5(A
W = 10
5K
5K
A
B
B
A - B
2
A - B
B + A
-B
A
2
)