®

MPY100

10

applied to the unused X-input (see Optional Trim Configu-

ration). To trim, apply a ramp of +100mV to +1V at 100Hz

otherwise reverse the signal polarity and adjust the trim

voltage to minimize the variation in the output. An alterna-

tive to this procedure would be to use the Burr-Brown

DIV100, a precision log-antilog divider.

FIGURE 9. Squarer Connection.

SQUARING

MPY100

Y

2

Y

1

X

2

X

1

Z

1

Z

2

Out

V

(X

2

V

+ Z

2

10

Optional

Summing

Input, ±10V, FS

V

X

±10V, FS

MPY100

Y

2

Y

1

X

2

X

1

Z

1

Z

2

Out

V

O

1k

Ω

+0.2V

≤ V

V

1

V

2

9k

Ω

(V

V

100

V

1

1% per volt

SQUARE ROOT

Figure 10 shows the connection for taking the square root of

which could occur if the input momentarily changed polar-

ity. This latching condition is not a design flaw in the

MPY100, but occurs when a multiplier is connected in the

feedback loop of an operational amplifier to perform square

root functions.

10k

Ω ≤ R

it provides the current necessary to operate the diode.

PERCENTAGE COMPUTATION

The circuit of Figure 11 has a sensitivity of 1V/% and is

capable of measuring 10% deviations. Wider deviation can

BRIDGE LINEARIZATION

The use of the MPY100 to linearize the output from a bridge

supply voltage. See Figure 12.

TRUE RMS-TO-DC CONVERSION

The rms-to-DC conversion circuit of Figure 13 gives greater

accuracy and bandwidth but with less dynamic range than

most rms-to-DC converters.

SINE FUNCTION GENERATOR

The circuit in Figure 14 uses implicit feedback to implement

the following sine function approximation:

MORE CIRCUITS

The theory and procedures for developing virtually any

function generator or linearization circuit can be found in the

Burr-Brown/McGraw Hill book “FUNCTION CIRCUITS -

Design and Applications.”

MPY100

Y

2

Y

1

X

2

X

1

Z

1

Z

2

Out

V

O

V

10(Z

(a) Circuit for positive V

Optional

Summing

Input,

±10V, FS

V

Z

R

L

+0.2V

≤ (Z

MPY100

Y

2

Y

1

X

2

X

1

Z

1

Z

2

Out

V

O

V

10(Z

(b) Circuit for negative V

Optional

Summing

Input,

±10V, FS

V

Z

R

L

+0.2V

≤ (Z

FIGURE 10. Square Root Connection.

FIGURE 11. Percentage Computation.