®

MPY534

7

Accuracy of the divider mode typically ranges from 0.75%

to 2.0% 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 a 100 to 1 denominator

range. To trim, apply a signal which varies from 100mV to

10V at a low frequency (less than 500Hz) to both inputs. 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

Ω must be provided. Trimming for im-

proved accuracy would be accomplished at the Z input.

FIGURE 4. Basic Divider Connection.

FIGURE 5. Square-Rooter Connection.

FIGURE 6. Difference-of-Squares.

APPLICATIONS

FIGURE 7. Voltage-Controlled Amplifier.

FIGURE 8. Sine-Function Generator.

MPY534

X

1

+V

S

X

2

Out

SF

Z

1

Y

1

Z

2

Y

2

–V

S

–15V

+15V

4.7k

Ω

4.3k

Ω

3k

Ω

10k

Ω

18k

Ω

V

Where

= (

π/2) (E /10V)

θ

θ

θ

Input, E

0 to +10V

θ

MPY534

X

1

+V

S

X

2

Out

SF

Z

1

Y

1

Z

2

Y

2

–V

S

–V

S

–15V

+15V

2k

Ω

E

39k

Ω

1k

Ω

V

= (E

0.005µF

1k

Ω

Signal Input,

E

Control Input,

Set

Gain

NOTES: (1) Gain is X10 per volt of E

(10Hz to 30Hz) output noise is 3mVrms, typ, corresponding to a FS

S/N ratio of 70dB. (3) Noise referred to signal input, with E

is 60µVrms, typ. (4) Bandwidth is DC to 20kHz, –3dB, indepedent

of gain.

MPY534

X

1

+V

S

X

2

Out

SF

Z

1

Y

1

Z

2

Y

2

–V

S

–15V

+15V

Optional

Summing Input

±10V PK

X Input

(Denominator)

±10V FS

±12V PK

Z Input

(Numerator)

±10V FS,

±12V PK

+

–

(X

V

+ Y

1

10V(Z

Output, ±12V PK

MPY634

X

1

+V

S

X

2

Out

SF

Z

1

Y

1

Z

2

Y

2

–V

S

–15V

+15V

Z Input

10V FS

12V PK

V

10V(Z

Output, ±12V PK

R

L

(Must be

Provided)

Reverse

this and

X inputs

for

Negative

Outputs

Optional

Summing

Input, X,

±10V PK

1k

Ω

400pF

MPY534

X

1

+V

S

X

2

Out

SF

Z

1

Y

1

Z

2

Y

2

–V

S

10k

Ω

–15V

+15V

V

10k

Ω

A

B

(A + B)

2

30k

Ω

10k

Ω

A – B

2