®

MPY534

5

10

0

–10

–20

–30

10k

100k

1M

10M

Frequency (Hz)

FREQUENCY RESPONSE AS A MULTIPLIER

C

C

C

With X10

Feedback

Attenuator

0dB = 0.1Vrms; R

Normal

Connection

C

C

C

14

12

10

8

6

4

8

Positive or Negative Supply (V)

INPUT/OUTPUT SIGNAL RANGE

vs SUPPLY VOLTAGES

10

12

14

16

18

20

Output, R

All Inputs, SF = 10V

50

40

30

20

10

0

–10

–20

1k

10k

1M

10M

Frequency (Hz)

FREQUENCY RESPONSE

vs DIVIDER DENOMINATOR INPUT VOLTAGE

100k

V

V

V

V

V

V

1.5

1.25

1

0.75

0.5

10

100

10k

100k

Frequency (Hz)

NOISE SPECTRAL DENSITY

vs FREQUENCY

1k

THEORY OF OPERATION

The transfer function for the MPY534 is:

V

– (Z

where:

A = Open-loop gain of the output amplifier

(typically 85dB at DC).

SF = Scale Factor. Laser-trimmed to 10V but

adjustable over a 3V to 10V range using

external resistor.

X, Y, A are input voltages. Full-scale input voltage

is equal to the selected SF. (Max input voltage =

±1.25 SF.)

An intuitive understanding of transfer function can be gained

by analogy to an op amp. By assuming that the open-loop

gain, A, of the output amplifier is infinite, inspection of the

transfer function reveals that any V

an infinitesimally small quantity within the brackets. Then,

(X

SF

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, Z

within the brackets then reduces to:

– (V

This approach leads to a simple relationship which can be

solved for V

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 –V

external resistor can be approximated by:

R

(X

SF

10 – SF

SF