ha3-2556-9 Intersil Corporation, ha3-2556-9 Datasheet - Page 8

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

This multiplier has the advantage over other AGC circuits, in
that the signal bandwidth is not affected by the control signal
gain adjustment.
Voltage Controlled Amplifier
A wide range of gain adjustment is available with the Voltage
Controlled Amplifier configuration shown in Figure 16. Here
the gain of the HFA0002 can be swept from 20V/V to a gain
of almost 1000V/V with a DC voltage from 0V to 5V.
1N914
5k
FIGURE 16. VOLTAGE CONTROLLED AMPLIFIER
V
OUT
FIGURE 15. AUTOMATIC GAIN CONTROL
20k
V
+15V
NC
NC
NC
V-
Y
10k
+
NC
NC
NC
V-
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
HFA0002
REF
Y
50
HA-2556
REF
Y
HA-2556
0.1 F
10k
+
-
0.01 F
8
+
X
+
-
Z
-
5k
+
-
HA-5127
X
Z
16
15
14
13
12
11
10
9
0.1 F
16
15
14
13
12
11
10
NC
NC
NC
V+
9
500
V+
NC
NC
NC
V
X
+ (V
GAIN
5.6V
)
V
IN
V
OUT
HA-2556
Wave Shaping Circuits
for the analog multiplier. For example, where a nonlinear
sensor requires corrective curve fitting to improve linearity
the HA-2556 can provide nonintegral powers in the range 1
to 2 or nonintegral roots in the range 0.5 to 1.0 (refer to
References). This effect is displayed in Figure 17.
A multiplier can’t do nonintegral roots “exactly”, but it can
yield a close approximation. We can approximate
nonintegral roots with equations of the form:
Figure 18 compares the function V
approximation V
This function can be easily built using an HA-2556 and a
potentiometer for easy adjustment as shown in Figures 19 and
20. If a fixed nonintegral power is desired, the circuit shown in
Figure 21 eliminates the need for the output buffer amp. These
circuits approximate the function V
nonintegral power or root.
V
FIGURE 18. COMPARE APPROXIMATION TO NONINTEGRAL
Wave shaping or curve fitting is another class of application
V
FIGURE 17. EFFECT OF NONINTEGRAL POWERS / ROOTS
o
o
=
0.8
0.6
0.4
0.2
0.8
0.6
0.4
0.2
=
1
0
1
0
1 –
0
0
1 –
V
ROOT
V
IN
1 2
X
IN
2
0.7
OUT
0.2
+
0.2
+
V
V
IN
= 0.5V
IN
X
X
0.4
0.4
0.5
IN
INPUT (V)
INPUT (V)
0.5
X
0.7
+ 0.5V
IN
M
0.5X
OUT
0.6
where M is the desired
0.6
0.5
X
= V
IN
2
+ 0.5X
.
IN
0.7
X
0.8
1.5
0.8
to the
1
1