AD632

–5–

REV. A

Feedback attenuation also retains the capability for adding a

signal to the output. Signals may be applied to the Z terminal,

where they are amplified by –10, or to the common ground

connection where they are amplified by –1. Input signals may

also be applied to the lower end of the 2.7 k

Ω resistor, giving a

gain of +9.

Figure 6. Connections for Scale-Factor of Unity

OPERATION AS A DIVIDER

Figure 7 shows the connection required for division. Unlike

earlier products, the AD632 provides differential operation on

both numerator and denominator, allowing the ratio of two

floating variables to be generated. Further flexibility results from

dividers based on the use of a multiplier in a feedback loop, the

bandwidth is proportional to the denominator magnitude, as

shown in Figure 3.

Figure 7. Basic Divider Connection

Without additional trimming, the accuracy of the AD632B is

sufficient to maintain a 1% error over a 10 V to 1 V denomina-

tor range (The AD535 is functionally equivalent to the AD632

and has guaranteed performance in the divider and square-rooter

configurations and is recommended for such applications).

This range may be extended to 100:1 by simply reducing the X

offset with an externally generated trim voltage (range required

is

±3.5 mV max) applied to the unused X input. To trim, apply

used for offset adjustment, otherwise reverse the signal polarity)

and adjust the trim voltage to minimize the variation in the

output.*

Since the output will be near +10 V, it should be ac-coupled for

this adjustment. The increase in noise level and reduction in

bandwidth preclude operation much beyond a ratio of 100 to 1.

*See the AD535 data sheet for more details.