HA1-2556-9 Intersil, HA1-2556-9 Datasheet - Page 8

• Manufacturer Part Number: HA1-2556-9
• Description: IC MULTIPLIER 4QUAD VOUT 16-DIP
• Manufacturer: Intersil
• Series: HAr

Specifications of HA1-2556-9

• Function: Analog Multiplier
• Number Of Bits/stages: 4-Quadrant
• Package / Case: 16-CDIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Each input X, Y and Z have similar wide bandwidth and input
characteristics. This is unlike earlier products where one
input was dedicated to a slow moving control function as is
required for Automatic Gain Control. The HA-2556 is
versatile enough for both.
Although the X and Y inputs have similar AC characteristics,
they are not the same. The designer should consider input
parameters such as small signal bandwidth, AC feedthrough
and 0.1dB gain flatness to get the most performance from
the HA-2556. The Y-Channel is the faster of the two inputs
with a small signal bandwidth of typically 57MHz vs 52MHz
for the X-Channel. Therefore in AM Signal Generation, the
best performance will be obtained with the Carrier applied to
the Y-Channel and the modulation signal (lower frequency)
applied to the X-Channel.
Scale Factor Control
The HA-2556 is able to operate over a wide supply voltage
range ±5V to ±17.5V. The ±5V range is particularly useful in
video applications. At ±5V the input voltage range is reduced
to ±1.4V. The output cannot reach its full scale value with
this restricted input, so it may become necessary to modify
the scale factor. Adjusting the scale factor may also be
useful when the input signal itself is restricted to a small
portion of the full scale level. Here, we can make use of the
high gain output amplifier by adding external gain resistors.
Generating the maximum output possible for a given input
signal will improve the Signal-to-Noise Ratio and Dynamic
Range of the system. For example, let’s assume that the
input signals are 1V
the HA-2556 will be 200mV. (1V x 1V)/(5V) = 200mV. It
would be nice to have the output at the same full scale as
our input, so let’s add a gain of 5 as shown in Figure 9.
One caveat is that the output bandwidth will also drop by this
factor of 5. The multiplier equation then becomes
Equation 15:
Current Output
Another useful circuit for low voltage applications allows the
user to convert the voltage output of the HA2556 to an output
current. The HA-2557 is a current output version offering
W
A
B
=
5AB
----------- -
5
=
V
V
V
V
A B
Y
Y
X
X
+
-
FIGURE 9. EXTERNAL GAIN OF 5
+
-
×
1/5V
+
+
-
-
ExternalGain
PEAK
X
Y
each then, the maximum output for
HA-2556
8
+
-
=
∑
------- -
R
R
Z
G
F
+
A
1
+
-
V
V
V
OUT
Z
Z
+
-
(EQ. 15)
1kΩ
250Ω
R
R
F
G
W
HA-2556
100MHz of bandwidth, but its scale factor is fixed and does not
have an output amplifier for additional scaling. Fortunately, the
circuit in Figure 10 provides an output current that can be
scaled with the value of R
impedance of typically 1MΩ. I
Video Fader
The Video Fader circuit provides a unique function. Here
Channel 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
Channel B that are mixed together to produce a resulting
video image or other signal.
The Balance equation looks like Equation 17:
Which simplifies to Equation 18:
When V
ChA is removed, conversely when V
becomes V
≤ V
Other Applications
As previously shown, a function may contain several
different operators at the same time and use only one
I
(
V
OUT
V
ChA
ChB
OUT
A
MIX
B
MIX
=
)
=
×
≤ 5V the output is a blend of ChA and ChB.
MIX
A
------------- -
V
V
V
V
(
ChB
V
V
X
X
Y
Y
ChA ChB
×
5
-
Y
Y
+
-
+
+
-
-15V
OUT
B
1/5V
is 0V the equation becomes V
NC
NC
NC
MIX
×
+
–
+
+
-
-
FIGURE 10. CURRENT OUTPUT
------------------------------- -
R
V
------------- - ChA ChB
= ChA eliminating ChB. For V
MIX
CONVERT
will control the percentage of Channel A and
5
FIGURE 11. VIDEO FADER
1
)
1
2
3
4
5
6
7
8
(
X
Y
=
HA-2556
REF
5 V
+
-
CONVERT
(
–
50Ω
+
OUT
Σ
OUT
+
-
∑
-
)
Z
–
+
+
-
-
then becomes Equation 16:
ChB
and provides an output
16
15
14
13
12
11
10
A
9
MIX
+
-
)
V
V
OUT
V
V
is 5V the equation
X
V
V
OUT
Z
Z
NC
NC
NC
+15V
+
Z
Z
+
-
+
-
(0V TO 5V)
R
MIX
= ChB and
CONVERT
V
MIX
values 0V
April 29, 2008
(EQ. 16)
(EQ. 17)
(EQ. 18)
V
FN2477.6
OUT
I
OUT