HA1-2556/883 INTERSIL [Intersil Corporation], HA1-2556/883 Datasheet - Page 15

• Manufacturer Part Number: HA1-2556/883
• Description: Wideband Four Quadrant Analog Multiplier (Voltage Output)
• Manufacturer: INTERSIL [Intersil Corporation]

DESIGN INFORMATION
The information contained in this section has been developed through characterization by Intersil Semiconductor and is for use as
application and design information only. No guarantee is implied.
Current Output
Another useful circuit for low voltage applications allows the
user to convert the voltage output of the HA2556 to an out-
put current. The HA-2557 is a current output version offering
100MHz of bandwidth, but its scale factor is fixed and does
not have an output amplifier for additional scaling. Fortu-
nately the circuit in Figure 10 provides an output current that
can be scaled with the value of R
output impedance of typically 1M . The equation for I
becomes:
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
will 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 VMIX is 5V the equation
becomes V
VMIX
A
B
V
MIX
V
V
V
V
MIX
Y
Y
X
X
V
5V the output is a blend of Ch A and Ch B.
+
-
+
-
OUT
OUT
1/5V
is 0V the equation becomes V
I
OUT
+
+
-
-
FIGURE 10. CURRENT OUTPUT
= Ch A eliminating Ch B. For VMIX values 0V
=
ChA
X
Y
=
ChB
HA-2556
–
A
----------- -
ChB
5
+
+
B
-
V
---------- -
MIX
5
Z
-------------------------- -
R
=
CONVERT
CONVERT
A
ChA
5 V
+
-
V
1
OUT
V
V
OUT
–
Z
Z
OUT
+
-
and provides an
ChB
R
(Continued)
CONVERT
–
= Ch B and
ChB
HA2556
I
OUT
OUT
MIX
8-21
B
R1 and R2 set scale to 1V/%, other scale factors possible
for A
FIGURE 14. DIFFERENCE DIVIDED BY SUM (FOR A + B 0V)
A
CH A
CH B
5K
5K
A
R1
5K
5K
5K
0V.
V
V
V
V
V
V
V
V
V
V
X
Y
Y
FIGURE 12. DIFFERENCE OF SQUARES
X
Y
Y
X
Y
Y
V
V
X
FIGURE 13. PERCENTAGE DEVIATION
V
V
+
-
-15V
-
+
+
-
+
+
-
-
X
X
Y
Y
NC
NC
NC
1/5V
+
-
+
-
1/5V
1/5V
95K
+
+
-
-
FIGURE 11. VIDEO FADER
+
-
+
-
+
+
-
-
R2
1
2
3
4
5
6
7
8
X
Y
X
Y
X
Y
HA-2556
REF
+
-
HA-2556
HA-2556
50
+
+
+
-
+
-
-
-
Spec Number
+
+
-
-
Z
Z
Z
16
15
14
13
12
11
10
9
A
+
A
-
A
V
V
V
+
-
+
-
X
V
Z
Z
V
NC
NC
NC
+
+15V
V
V
OUT
+
-
V
V
OUT
Z
Z
Z
Z
V
V
(0V to 5V)
+
-
+
-
Z
Z
+
-
V
MIX
511063-883
W = 100
W = 5(A
W = 10
5K
5K
V
B
A
B
B + A
2
A - B
A - B
OUT
-B
A
2
)