Data Sheet

AD532

Rev. E | Page 11 of 14

APPLICATIONS

The performance and ease of use of the AD532 is achieved through

the laser trimming of thin film resistors deposited directly on

the monolithic chip. This trimming on the chip technique provides

a number of significant advantages in terms of cost, reliability,

and flexibility over conventional in package trimming of off the

chip resistors mounted or deposited on a hybrid substrate.

Trimming on the chip eliminates the need for a hybrid substrate

and the additional bonding wires that are required between the

resistors and the multiplier chip. By trimming more appropriate

resistors on the AD532 chip itself, the second input terminals

that were committed to external trimming networks have been

freed to allow fully differential operation at both the X and Y

inputs. Further, the requirement for an input attenuator to

adjust the gain at the Y input has been eliminated, letting the

user take full advantage of the high input impedance properties

of the input differential amplifiers. Therefore, the AD532 offers

greater flexibility for both algebraic computation and transducer

instrumentation applications.

Provision for fine trimming the output voltage offset has been

included. This connection is optional, however, as the AD532 has

been factory trimmed for total performance as described in the

listed specifications.

REPLACING OTHER IC MULTIPLIERS

Existing designs using IC multipliers that require external

trimming networks can be simplified using the pin for pin

replaceability of the AD532 by merely grounding the X2, Y2,

and VOS terminals. The VOS terminal must always be grounded

when unused.

Multiplication

Z

OUT

AD532

X1

X2

Y1

Y2

VOUT

VOS

20kΩ

+VS

–VS

VOUT =

(X1 – X2) (Y1 – Y2)

10V

(OPTIONAL)

Figure 14. Multiplier Connection

For operation as a multiplier, the AD532 must be connected as

shown in Figure 14. The inputs can be fed differentially to the X

and Y inputs or single-ended by simply grounding the unused

input. Connect the inputs according to the desired polarity in

the output. The Z terminal is tied to the output to close the

feedback loop around the op amp (see Figure 1). The offset adjust

VOS is optional and is adjusted when both inputs are zero volts

to obtain zero out, or to null other system offsets.

Squaring

AD532

X1

X2

Y1

Y2

VOUT

20kΩ

+VS

–VS

+VS

–VS

VOS

VOUT =

VIN2

10V

(OPTIONAL)

Z

OUT

VIN

Figure 15. Squarer Connection

The squaring circuit in Figure 15 is a simple variation of the

multiplier. The differential input capability of the AD532, however,

can obtain a positive or negative output response to the input, a

useful feature for control applications, as it might eliminate the

need for an additional inverter somewhere else.

Division

AD532

20kΩ

(X0)

47kΩ

2.2kΩ

10kΩ

1kΩ

(SF)

+VS

–VS

+VS

–VS

VOUT =

10VZ

X

Z

OUT

Z

VOUT

X

X1

X2

Y1

Y2

Figure 16. Divider Connection

The AD532 can be configured as a two-quadrant divider by

connecting the multiplier cell in the feedback loop of the op

amp and using the Z terminal as a signal input, as shown in

Figure 16. It should be noted, however, that the output error is

given approximately by 10 V εm/(X1 − X2), where εm is the total

error specification for the multiply mode and bandwidth by fm ×

(X1 − X2)/10 V, where fm is the bandwidth of the multiplier.

Further, to avoid positive feedback, the X input is restricted to

negative values. Thus, for single-ended negative inputs (0 V to

−10 V), connect the input to X and the offset null to X2; for single-

ended positive inputs (0 V to +10 V), connect the input to X2

and the offset null to X1. For optimum performance, gain (SF)

and offset (X0) adjustments are recommended as shown and

explained in Table 5.

For practical reasons, the useful range in denominator input is

approximately 500 mV ≤ |(X1 − X2)| ≤ 10 V. The voltage offset

adjust (VOS), if used, is trimmed with Z at zero and (X1 − X2) at

full scale.