ha3-2556-9 Intersil Corporation, ha3-2556-9 Datasheet - Page 5

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

Typical Applications
Let’s first examine the Balance Concept as it applies to the
standard multiplier configuration (Figure 2).
Signals A and B are input to the multiplier and the signal W
is the result. By substituting the signal values into the
Balance equation you get:
And solving for W:
Notice that the output (W) enters the equation in the
feedback to the Z stage. The Balance Equation does not test
for stability, so remember that you must provide negative
feedback. In the multiplier configuration, the feedback path is
connected to V
that takes place at the summing node just prior to the output
amplifier. Feedback is not restricted to the Z stage, other
feedback paths are possible as in the Divider Configuration
shown in Figure 3.
Inserting the signal values A, B and W into the Balance
Equation for the divider configuration yields:
Solving for W yields:
Notice that, in the divider configuration, signal B must remain
negative, then it will be multiplied by the V
positive feedback and the output will swing into the rail.
Signals may be applied to more than one input at a time as
in the Squaring configuration in Figure 4:
(A) x (B) = 5(W)
W =
W =
-W
0 (positive) for the feedback to be negative. If signal B is
A
B
B
A x B
------------- -
5A
------ -
B
B
5
=
V
V
V
V
V
V
V
V
5V x -A
X
X
Y
Y
X
X
Y
Y
+
-
+
-
+
-
+
-
1/5V
1/5V
Z
+ input, not V
+
+
+
+
-
-
-
-
FIGURE 2. MULTIPLIER
FIGURE 3. DIVIDER
Y
X
Y
X
HA-2556
HA-2556
Z
5
+
+
-. This is due to the inversion
-
-
Z
Z
A
A
+
-
+
-
X-
V
V
input to produce
V
V
OUT
V
V
OUT
Z
Z
Z
Z
+
-
+
-
A
W
W
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Here the Balance equation will appear as:
Which simplifies to:
The last basic configuration is the Square Root as shown in
Figure 5. Here feedback is provided to both X and Y inputs.
The Balance equation takes the form:
Which equates to:
The four basic configurations (Multiply, Divide, Square and
Square Root) as well as variations of these basic circuits
have many uses.
Frequency Doubler
For example, if ACos(
Square function, then it becomes a Frequency Doubler and
the equation takes the form:
And using some trigonometric identities gives the result:
(A) x (A)
W
W
W
W
A
ACos
=
=
=
A
------ -
A
------ - 1
10
5
–
5A
2
2
W
=
+
5(W)
FIGURE 5. SQUARE ROOT (FOR A > 0)
=
V
V
V
V
V
V
V
V
Cos 2
X
X
Y
Y
X
X
Y
Y
5 A
+
+
-
-
+
-
+
-
ACos
1/5V
1/5V
–
+
+
-
-
+
+
-
-
FIGURE 4. SQUARE
Y
X
Y
) is substituted for signal A in the
X
=
HA-2556
HA-2556
5 W
+
+
-
-
Z
Z
A
A
+
-
+
-
V
V
V
V
OUT
V
V
OUT
Z
Z
Z
Z
+
-
+
-
A
W
W