Burr-Brown MPY634SM Wide bandwidth precision analog multiplier Datasheet

MPY634
®
Wide Bandwidth
PRECISION ANALOG MULTIPLIER
FEATURES
DESCRIPTION
● WIDE BANDWIDTH: 10MHz typ
● ±0.5% MAX FOUR-QUADRANT
ACCURACY
● INTERNAL WIDE-BANDWIDTH OP AMP
● EASY TO USE
● LOW COST
The MPY634 is a wide bandwidth, high accuracy,
four-quadrant analog multiplier. Its accurately lasertrimmed multiplier characteristics make it easy to use
in a wide variety of applications with a minimum of
external parts, often eliminating all external trimming.
Its differential X, Y, and Z inputs allow configuration
as a multiplier, squarer, divider, square-rooter, and
other functions while maintaining high accuracy.
APPLICATIONS
The wide bandwidth of this new design allows signal
processing at IF, RF, and video frequencies. The
internal output amplifier of the MPY634 reduces
design complexity compared to other high frequency
multipliers and balanced modulator circuits. It is
capable of performing frequency mixing, balanced
modulation, and demodulation with excellent carrier
rejection.
● PRECISION ANALOG SIGNAL
PROCESSING
● MODULATION AND DEMODULATION
● VOLTAGE-CONTROLLED AMPLIFIERS
● VIDEO SIGNAL PROCESSING
● VOLTAGE-CONTROLLED FILTERS AND
OSCILLATORS
An accurate internal voltage reference provides
precise setting of the scale factor. The differential Z
input allows user-selected scale factors from 0.1 to 10
using external feedback resistors.
+VS
Voltage
Reference
and Bias
SF
–VS
X1
Transfer Function
V-I
X2
VOUT = A
(X1 – X2)(Y1 – Y2)
SF
Multiplier
Core
– (Z1 – Z2)
Y1
V-I
Y2
A
Z1
V-I
0.75 Atten
VOUT
Precision
Output
Op Amp
Z2
International Airport Industrial Park • Mailing Address: PO Box 11400 • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706
Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
®
©
1985 Burr-Brown Corporation
1
PDS-636D
MPY634
Printed in U.S.A. December, 1995
SPECIFICATIONS
ELECTRICAL
At TA = +25°C and VS = ±15VDC, unless otherwise noted.
MPY634KP/KU
MODEL
MIN
MULTIPLIER
PERFORMANCE
Transfer Function
Total Error(1)
(–10V ≤ X, Y ≤ +10V)
TA = min to max
Total Error vs Temperature
Scale Factor Error
(SF = 10.000V Nominal)(2)
Temperature Coefficient of
Scaling Voltage
Supply Rejection (±15V ±1V)
Nonlinearity
X (X = 20Vp-p, Y = 10V)
Y (Y = 20Vp-p, X = 10V)
Feedthrough(3)
X (Y Nulled, X = 20Vp-p, 50Hz)
Y (X Nulled, Y = 20Vp-p, 50Hz)
Both Inputs (500kHz, 1Vrms)
Unnulled
Nulled
Output Offset Voltage
Output Offset Voltage Drift
DYNAMICS
Small Signal BW,
(VOUT = 0.1Vrms)
1% Amplitude Error
(CLOAD = 1000pF)
Slew Rate (VOUT = 20Vp-p)
Settling Time
(to 1%, ∆VOUT = 20V)
INPUT AMPLIFIERS (X, Y and Z)
Input Voltage Range
Differential VIN (VCM = 0)
Common-Mode VIN (VDIFF = 0)
(see Typical Performance Curves)
Offset Voltage X, Y
Offset Voltage Drift X, Y
Offset Voltage Z
Offset Voltage Drift Z
CMRR
Bias Current
Offset Current
Differential Resistance
DIVIDER PERFORMANCE
Transfer Function (X1 > X2)
Total Error (1) untrimmed
(X = 10V, –10V ≤ Z ≤ +10V)
(X = 1V, –1V ≤ Z ≤ +1V)
(0.1V≤ X ≤ 10V, –10V ≤ Z ≤ 10V)
MAX
±2.5
±0.03
40(4)
55(4)
6(4)
TYP
10V
±2.0
±1.5
±0.022
MAX
MIN
+ Z2
TYP
MPY634SM
MAX
MIN
*
±1.0
±1.0
±0.015
TYP
MAX
UNITS
*
±2.0
±0.02
%
%
%/°C
*
±0.5
±0.1
*
*
%
±0.02
*
±0.01
±0.01
±0.01
*
*
*
%/°C
%
*
*
±0.4
±0.01
0.2
*
±0.3
±0.1
*
*
%
%
*
*
±0.3
±0.01
±0.15
*
±0.3
±0.1
*
*
%
%
*
*
*
*
dB
dB
mV
µV/°C
50
60
±50
*
45
55
±100
*
8
55
65
±5
±200
*
60
±30
10
*
60
70
*
±100
*
*
±15
*
6
*
±500
*
MHz
*
*
100
20
*
*
*
*
kHz
V/µs
*
2
*
*
µs
*
0.8
*
*
µV/√Hz
*
*
1
90
*
*
*
*
mVrms
µVrms
±11
*
0.1
*
*
V
Ω
*
30
*
*
mA
*
85
*
*
dB
*
*
±12
±10
*
*
*
*
V
V
±25
200
±25
*
*
*
*
*
*
1.5
4.0
5.0
±100
±100
60
*
10V
*
±5
100
±5
200
80
0.8
0.1
10
(Z2 – Z1)
(X1 – X2)
±20
±30
70
2.0
+ Y1
±0.75
±2.0
±2.5
(X1 – X2) 2
SQUARE PERFORMANCE
Transfer Function
*
10V
Total Error (–10V ≤ X ≤ 10V)
±1.2
±0.6
®
MPY634
MPY634BM
±0.25
*
*
MIN
(X1 – X2) (Y1 – Y2)
*
NOISE
Noise Spectral Density:
SF = 10V
Wideband Noise:
f = 10Hz to 5MHz
f = 10Hz to 10kHz
OUTPUT
Output Voltage Swing
Output Impedance (f ≤ 1kHz)
Output Short Circuit Current
(RL = 0, TA = min to max)
Amplifier Open Loop Gain
(f = 50Hz)
TYP
MPY634AM
2
+ Z2
*
±2
50
±2
100
90
*
*
*
±10
*
*
*
±15
*
*
*
*
*
*
*
*
±0.35
±1.0
±1.0
±0.75
*
*
*
*
±0.3
*
*
*
500
*
2.0
mV
µV/°C
mV
µV/°C
dB
µA
µA
MΩ
%
%
%
%
SPECIFICATIONS (CONT)
ELECTRICAL
At TA = +25°C and VS = ±15VDC, unless otherwise noted.
MPY634KP/KU
MODEL
MIN
SQUARE-ROOTER
PERFORMANCE
Transfer Function (Z1 ≤ Z2)
Total Error(1) (1V ≤ Z ≤ 10V)
TYP
MPY634AM
MAX
MIN
TYP
MPY634BM
MAX
MIN
TYP
MPY634SM
MAX
MIN
TYP
MAX
UNITS
√10V (Z2 – Z1) +X2
*
±2.0
POWER SUPPLY
Supply Voltage:
Rated Performance
Operating
Supply Current, Quiescent
*
*
*
±8
*(5)
+85
–25
–65
*
*
TEMPERATURE RANGE
Specification
Storage
*
±0.5
±1.0
*(5)
–40
±15
*
*
*
4
±18
6
*
+85
+150
*
*
%
*
*
*
*
*
*
*
–55
*
*
±20
*
VDC
VDC
mA
+125
*
°C
°C
* Specification same as for MPY634AM.
NOTES: (1) Figures given are percent of full scale, ±10V (i.e., 0.01% = 1mV). (2) May be reduced to 3V using external resistor between –VS and SF. (3) Irreducible
component due to nonlinearity; excludes effect of offsets. (4) KP grade only. (5) KP grade only. 0°C to +70°C for KU grade.
PIN CONFIGURATIONS
Top View
X1 Input
1
16 +VS
X1 Input
1
14 +VS
X2 Input
2
15 NC
X2 Input
2
13 NC
NC
3
14 Output
NC
3
12 Output
Scale Factor
4
13 Z1 Input
Scale Factor
4
11 Z1 Input
NC
5
12 Z2 Input
NC
5
10 Z2 Input
Y1 Input
6
11 NC
Y1 Input
6
9
NC
Y2 Input
7
10 –VS
Y2 Input
7
8
–VS
NC
8
9
X1
X2
10
+VS
9
1
SF
2
8
Out
Y1
3
7
Z1
Y2
6
4
5
Z2
–VS
TO-100: MPY634AM/BM/SM
DIP: MPY634KP
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Power Supply Voltage
Power Dissipation
Output Short-Circuit
to Ground
Input Voltage ( all X,
Y and Z)
Temperature Range:
Operating
Storage
Lead Temperature
(soldering, 10s)
SOIC ‘KU’ Package
NC
SOIC: MPY634KU
ORDERING INFORMATION
MPY634AM/BM MPY634KP/KU
MPY634SM
±18
500mW
*
*
±20
*
Indefinite
*
*
±VS
*
*
–25°C/+85°C
–65°C/+150°C
*
–40°C/+85°C
–55°C/+125°C
*
+300°C
*
+260°C
*
MPY634
( )
( )
Basic Model Number
Performance Grade(1)
K: –25°C to +85°C (‘U’ package 0°C to +70°C)
A: –25°C to +85°C
B: –25°C to +85°C
S: –55°C to +125°C
Package Code
M: TO-100 Metal
P: Plastic 14-pin DIP
U: 16-pin SOIC
NOTE: (1) Performance grade identifier may not be marked on the SOIC
package; a blank denotes “K” grade.
* Specification same as for MPY634AM/BM.
PACKAGE INFORMATION
PACKAGE DRAWING
MODEL
PACKAGE
NUMBER(1)
MPY634KP
14-Pin PDIP
010
MPY634KU
16-Pin SOIC
211
MPY634AM
TO-100
007
MPY634BM
TO-100
007
MPY634SM
TO-100
007
NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix D of Burr-Brown IC Data Book.
®
3
MPY634
TYPICAL PERFORMANCE CURVES
TA = +25°C, VS = ±15VDC, unless otherwise noted.
FREQUENCY RESPONSE AS A MULTIPLIER
FEEDTHROUGH vs FREQUENCY
10
–40
X Feedthrough
–60
Y Feedthrough
–80
–100
0
CL = 0pF
–10
With X10 Feedback
Attenuator
–20
–30
100
1k
100k
10k
1M
10M
1k
100M
10k
100k
Frequency (Hz)
1M
10M
100M
Frequency (Hz)
FEEDTHROUGH vs TEMPERATURE
COMMON-MODE REJECTION RATIO vs FREQUENCY
–50
90
70
Feedthrough Attenuation (dB)
80
CMRR (dB)
CL = 1000pF
Normal Connection
Output Response (dB)
Feedthrough Attenuation (dB)
–20
Typical for all inputs
60
50
40
30
20
–60
fY = 500kHz
VX = nulled
–70
nulled at 25°C
10
–80
0
10k
100
100M
1M
–60 –40 –20
10M
0
NOISE SPECTRAL DENSITY
vs FREQUENCY
40
60
80
100
120 140
FREQUENCY RESPONSE AS A DIVIDER
60
1.5
1.25
Output, V0 / V2 (dB)
Noise Spectral Density (µV/√Hz)
20
Temperature (°C)
Frequency (Hz)
1
VX = 100mVDC
VZ = 10mVrms
40
VX = 1VDC
VZ = 100mVrms
20
VX = 10VDC
VZ = 100mVrms
0
0.75
–20
0.5
10
1k
100
10k
1k
100k
10k
100k
1M
10M
100M
Frequency (Hz)
Frequency (Hz)
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN
assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject
to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not
authorize or warrant any BURR-BROWN product for use in life support devices and/or systems.
®
MPY634
4
TYPICAL PERFORMANCE CURVES (CONT)
TA = +25°C, VS = ±15VDC, unless otherwise noted.
INPUT DIFFERENTIAL-MODE/
COMMON-MODE VOLTAGE
INPUT/OUTPUT SIGNAL RANGE
vs SUPPLY VOLTAGES
10
Peak Positive or Negative Signal (V)
14
12
5
Output, RL ≥ 2kΩ
10
–12
–10
–5
VCM
Specified
Accuracy
5
All inputs, SF = 10V
10
12
VDIFF
8
VS = ±15V
–5
6
4
8
10
12
16
14
18
–10
Functional
Derated Accuracy
20
Positive or Negative Supply (V)
BIAS CURRENTS vs TEMPERATURE
(X,Y or Z Inputs)
800
Bias Current (nA)
700
600
500
Scaling Voltage = 10V
400
300
Scaling Voltage = 3V
200
100
0
–60 –40 –20
0
20
40
60
80
100 120 140
Temperature (°C)
THEORY OF OPERATION
inspection of the transfer function reveals that any VOUT can
be created with an infinitesimally small quantity within the
brackets. Then, an application circuit can be analyzed by
assigning circuit voltages for all X, Y and Z inputs and
setting the bracketed quantity equal to zero. For example,
the basic multiplier connection in Figure 1, Z1 = VOUT and
Z2 = 0. The quantity within the brackets then reduces to:
The transfer function for the MPY634 is:
VOUT = A
(X1 – X2) (Y1 – Y2)
SF
– (Z1 – Z2)
where:
(X1 – X2) (Y1 – Y2)
A = open-loop gain of the output amplifier (typically
85dB at DC).
SF
SF = Scale Factor. Laser-trimmed to 10V but adjustable
over a 3V to 10V range using external resistors.
– (VOUT – 0) = 0
This approach leads to a simple relationship which can be
solved for VOUT to provide the closed-loop transfer function.
X, Y, Z are input voltages. Full-scale input voltage
is equal to the selected SF. (Max input voltage =
±1.25 SF).
The scale factor is accurately factory adjusted to 10V and is
typically accurate to within 0.1% or less. The scale factor
may be adjusted by connecting a resistor or potentiometer
between pin SF and the –VS power supply. The value of the
external resistor can be approximated by:
An intuitive understanding of transfer function can be gained
by analogy to the op amp. By assuming that the open-loop
gain, A, of the output operational amplifier is infinite,
®
5
MPY634
RSF = 5.4kΩ
SF
X Input
±10V FS
±12V PK
10 – SF
Internal device tolerances make this relationship accurate to
within approximately 25%. Some applications can benefit
from reduction of the SF by this technique. The reduced
input bias current, noise, and drift achieved by this technique
can be likened to operating the input circuitry in a higher
gain, thus reducing output contributions to these effects.
Adjustment of the scale factor does not affect bandwidth.
+15V
470kΩ
The MPY634 is fully characterized at VS = ±15V but
operation is possible down to ±8V with an attendant reduction of input and output range capability. Operation at
voltages greater than ±15V allows greater output swing to be
achieved by using an output feedback attenuator (Figure 1).
X1
+VS
X2
Out
+15V
Y Input
±10V FS
±12V PK
Y1
Z2
Y2
–VS
X Input
±10V FS
±12V PK
Optional
Peaking
Capacitor
CF = 200pF
Y1
Z2
Y2
–VS
X1
+VS
=
10V
+ Z2
Optional
Summing
Input,
Z, ±10V PK
–15V
X2
Out
+15V
IOUT =
(X1 – X2) (Y1 – Y2)
10V
MPY634
SF
Z1
Y1
Z2
x
1
RS
–15V
FIGURE 1. Connections for Scale-Factor of Unity.
Y Input
±10V FS
±12V PK
BASIC MULTIPLIER CONNECTION
Figure 2 shows the basic connection as a multiplier. Accuracy is fully specified without any additional user-trimming
circuitry. Some applications can benefit from trimming of
one or more of the inputs. The fully differential inputs
facilitate referencing the input quantities to the source voltage common terminal for maximum accuracy. They also
allow use of simple offset voltage trimming circuitry as
shown on the X input.
Y2
–VS
–15V
Current
Sensing
Resistor,
RS, 2kΩ
min
Integrator
Capacitor
(see text)
FIGURE 3. Conversion of Output to Current.
SQUARER CIRCUIT (FREQUENCY DOUBLER)
Squarer, or frequency doubler, operation is achieved by
paralleling the X and Y inputs of the standard multiplier
circuit. Inverted output can be achieved by reversing the
differential input terminals of either the X or Y input.
Accuracy in the squaring mode is typically a factor of two
better than the specified multiplier mode with maximum
error occurring with small (less than 1V) inputs. Better
accuracy can be achieved for small input voltage levels by
reducing the scale factor, SF.
The differential Z input allows an offset to be summed in
VOUT. In basic multiplier operation, the Z2 input serves as
the output voltage ground reference and should be connected
to the ground of the driven system for maximum accuracy.
A method of changing (lowering) SF by connecting to the
SF pin was discussed previously. Figure 1 shows an alternative method of changing the effective SF of the overall
circuit by using an attenuator in the feedback connection to
Z1. This method puts the output amplifier in a higher gain
and is thus accompanied by a reduction in bandwidth and an
DIVIDER OPERATION
The MPY634 can be configured as a divider as shown in
Figure 4. High impedance differential inputs for the numerator and denominator are achieved at the Z and X inputs,
Hello
®
MPY634
Z1
The flexibility of the differential Z inputs allows direct
conversion of the output quantity to a current. Figure 3
shows the output voltage differentially-sensed across a series resistor forcing an output-controlled current. Addition
of a capacitor load then creates a time integration function
useful in a variety of applications such as power computation.
90kΩ
10kΩ
SF
VOUT, ±12V PK
(X1 – X2) (Y1 – Y2)
increase in output offset voltage. The larger output offset
may be reduced by applying a trimming voltage to the high
impedance input, Z2.
VOUT, ±12V PK
= (X1 – X2) (Y1 – Y2)
(Scale = 1V)
Z1
Out
FIGURE 2. Basic Multiplier Connection.
MPY634
SF
X2
+15V
1kΩ
Y Input
±10V FS
±12V PK
As with any wide bandwidth circuit, the power supplies
should be bypassed with high frequency ceramic capacitors.
These capacitors should be located as near as practical to the
power supply connections of the MPY634. Improper bypassing can lead to instability, overshoot, and ringing in the
output.
X Input
±10V FS
±12V PK
+VS
MPY634
50kΩ
–15V
Optional Offset
Trim Circuit
X1
6
respectively. Feedback is applied to the Y2 input, and Y1 is
normally referenced to output ground. Alternatively, as the
transfer function implies, an input applied to Y1 can be
summed directly into VOUT. Since the feedback connection
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 Performance Curves).
Output, ±12V PK
VOUT = 10V(Z2 – Z1) + X2
+15V
Optional
Summing
Input, X,
±10V PK
Reverse
this and
X inputs
for
Negative
Outputs
+VS
X1
X2
Out
MPY634
Output, ±12V PK
SF
Z1
Y1
Z2
Y2
–VS
RL
(Must be
Provided)
Z Input
10V FS
12V PK
+
X Input
(Denominator)
0.1V ≤ X ≤ 10V
–
X1
+VS
+15V
VOUT =
X2
10V(Z2 – Z1)
(X1 – X2)
+ Y1
Out
FIGURE 5. Square-Rooter Connection.
MPY634
Optional
Summing Input
±10V PK
–15V
SF
Z1
Y1
Z2
Y2
–VS
Z Input
(Numerator)
±10V FS,
±12V PK
APPLICATIONS
A sin (2π 10MHz t)
–15V
X1
+VS
X2
Out
+15V
1kΩ
FIGURE 4. Basic Divider Connection.
VO = (AB/20) cos θ
0.1µF
MPY634
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 (X2 for positive input voltages on X1) can
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.
SF
Z1
Y1
Z2
Y2
–VS
RX
B sin (2π 10MHz t + θ)
–15V
Multiplier connection followed by a low-pass filter forms phase
detector useful in phase-locked-loop circuitry. RX is often used in
PLL circuitry to provide desired loop-damping characteristics.
FIGURE 6. Phase Detector.
+15V
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 reversing the diode and X input polarity. A load resistance of
approximately 10kΩ must be provided. Trimming for improved accuracy would be accomplished at the Z input.
+
X1
+VS
VO = 10 • EC • ES
EC
–
2kΩ
X2
2kΩ
A1
MPY634
SF
Z1
Y1
Z2
Y2
–VS
–15V
+
OPA606
VO
39kΩ
1kΩ
ES
–
–15V
Minor gain adjustments are accomplished with the 1kΩ variable resistor
connected to the scale factor adjustment pin, SF. Bandwidth of this circuit
is limited by A1, which is operated at relatively high gain.
FIGURE 7. Voltage-Controlled Amplifier.
®
7
MPY634
Modulation
Input, ±EM
X1
+VS
X2
Out
18kΩ
MPY634
SF
Z1
Y1
Z2
10kΩ
VOUT = (10V) sinθ
Where
θ = (π/2) (Eθ /10V)
4.7kΩ
–VS
X2
Out
+15V
VOUT =
1 ± (EM/10V) EC sin ωt
SF
Z1
Y1
Z2
Y2
–VS
Carrier Input
EC sin ωt
3kΩ
Y2
+VS
MPY634
4.3kΩ
Input, Eθ
0 to +10V
X1
+15V
–15V
–15V
By injecting the input carrier signal into the output through connection
to the Z2 input, conventional amplitude modulation is achieved.
Amplification can be achieved by use of the SF pin, or Z attenuator
(at the expense of bandwidth).
With a linearly changing 0-10V input, this circuit’s output follows
0° to 90° of a sine function with a 10V peak output amplitude.
FIGURE 8. Sine-Function Generator.
FIGURE 9. Linear AM Modulator.
X1
+VS
X2
Out
+15V
(A2/20) cos (2 ω t)
A sin ω t
C
MPY634
SF
Z1
Y1
Z2
Y2
–VS
R
–15V
Frequency Doubler
Squaring a sinusoidal input creates an output frequency of
twice that of the input. The DC output component is
removed by AC-coupling the output.
Input Signal: 20Vp-p, 200kHz
Output Signal: 10Vp-p, 400kHz
FIGURE 10. Frequency Doubler.
Modulation
Input, ±EM
470kΩ
Carrier
Null
+15V
1kΩ
X1
+VS
X2
Out
+15V
VOUT
MPY634
SF
Z1
Y1
Z2
Y2
–VS
–15V
Carrier Input
EC sin ω t
–15V
The basic muliplier connection performs balanced modulation.
Carrier rejection can be improved by trimming the offset voltage
of the modulation input. Better carrier rejection above 2MHz is
typically achieved by interchanging the X and Y inputs (carrier
applied to the X input).
Carrier: fC = 2MHz, Amplitude = 1Vrms
Signal: fS = 120kHz, Amplitude = 10V peak
FIGURE 11. Balanced Modulator.
®
MPY634
8
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