MPY634AM BURR-BROWN [Burr-Brown Corporation], MPY634AM Datasheet - Page 7

• Manufacturer Part Number: MPY634AM
• Description: Wide Bandwidth PRECISION ANALOG MULTIPLIER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

respectively. Feedback is applied to the Y
normally referenced to output ground. Alternatively, as the
transfer function implies, an input applied to Y
summed directly into V
is made to a multiplying input, the effective gain of the
output op amp varies as a function of the denominator input
voltage. Therefore, the bandwidth of the divider function is
proportional to the denominator voltage (see Typical Perfor-
mance Curves).
FIGURE 4. Basic Divider Connection.
Accuracy of the divider mode typically ranges from 1.0% to
2.5% for a 10 to 1 denominator range depending on device
grade. Accuracy is primarily limited by input offset voltages
and can be significantly improved by trimming the offset of
the X input. A trim voltage of 3.5mV applied to the “low
side” X input (X
produce similar accuracies over 100 to 1 denominator range.
To trim, apply a signal which varies from 100mV to 10V at
a low frequency (less than 500Hz). An offset sine wave or
ramp is suitable. Since the ratio of the quantities should be
constant, the ideal output would be a constant 10V. Using
AC coupling on an oscilloscope, adjust the offset control for
minimum output voltage variation.
SQUARE-ROOTER
A square-rooter connection is shown in Figure 5. Input
voltage is limited to one polarity (positive for the connection
shown). The diode prevents circuit latch-up should the input
go negative. The circuit can be configured for negative input
and positive output by reversing the polarity of both the X
and Y inputs. The output polarity can be reversed by revers-
ing the diode and X input polarity. A load resistance of
approximately 10k
proved accuracy would be accomplished at the Z input.
0.1V
(Denominator)
Summing Input
X Input
±10V PK
X
Optional
10V
+
–
2
X
X
SF
Y
Y
for positive input voltages on X
1
2
1
2
MPY634
must be provided. Trimming for im-
OUT
+V
–V
Out
Z
Z
. Since the feedback connection
S
S
1
2
+15V
(Numerator)
–15V
±10V FS,
±12V PK
Z Input
Output, ±12V PK
V
OUT
2
=
input, and Y
10V(Z
(X
1
– X
2
1
– Z
2
)
can be
1
1
)
) can
+ Y
1
1
is
7
APPLICATIONS
FIGURE 7. Voltage-Controlled Amplifier.
FIGURE 5. Square-Rooter Connection.
FIGURE 6. Phase Detector.
Summing
±10V PK
B sin (2 10MHz t + )
Optional
Input, X,
–15V
Minor gain adjustments are accomplished with the 1k variable resistor
connected to the scale factor adjustment pin, SF. Bandwidth of this circuit
is limited by A
A sin (2 10MHz t)
Multiplier connection followed by a low-pass filter forms phase
detector useful in phase-locked-loop circuitry. R
PLL circuitry to provide desired loop-damping characteristics.
2k
1
, which is operated at relatively high gain.
E
E
+
–
+
–
C
S
X
X
SF
Y
Y
2k
1
2
1
2
MPY634
X
X
SF
Y
Y
1
2
1
2
MPY634
+V
–V
Out
X
X
SF
Y
Y
Z
Z
1
2
1
2
MPY634
S
S
1
2
+V
–V
Out
Z
Z
S
1
2
S
+15V
+V
–V
Z
V
Z
MPY634
O
S
S
1
2
–15V
Z Input
10V FS
12V PK
+15V
–15V
1k
V
+15V
–15V
Reverse
Negative
this and
X inputs
OUT
Outputs
X
for
is often used in
= 10V(Z
V
1k
Output, ±12V PK
O
V
= (AB/20) cos
O
R
A
= 10 • E
0.1µF
39k
X
1
2
(Must be
Provided)
– Z
OPA606
1
R
C
) + X
L
• E
2
S
®