Datasheet

AD534 Data Sheet
Rev. D | Page 14 of 20
As with the multiplier connection, overall gain can be introduced
by inserting a simple attenuator between the output and Y
2
terminal. This option and the differential ratio capability of the
AD534 are used in the percentage computer application shown
in Figure 24. This configuration generates an output propor-
tional to the percentage deviation of one variable (A) with
respect to a reference variable (B), with a scale of 1% per volt.
OPERATION AS A SQUARE ROOTER
The operation of the AD534 in the square root mode is shown
in Figure 19. The diode prevents a latching condition, which
may occur if the input momentarily changes polarity. As shown,
the output is always positive; it can be changed to a negative
output by reversing the diode direction and interchanging the X
inputs. Because the signal input is differential, all combinations
of input and output polarities can be realized, but operation is
restricted to the one quadrant associated with each combination
of inputs.
AD534
+V
S
X
1
X
2
SF
Y
1
Y
2
OUT
Z
1
Z
2
–V
S
+15V
–15V
Z INPUT
±10V FS
±12V PK
REVERSE THIS
AND X INPUTS
FOR NEGATIVE
OUTPUTS
R
L
(MUST BE
PROVIDED)
OPTIONAL
SUMMING
INPUT
X
, ±10V PK
+
–
09675-011
OUTPUT, ±12V PK =
10V (Z
2
– Z
1
) + X
2
Figure 19. Square-Rooter Connection
In contrast to earlier devices, which were intolerant of capacitive
loads in the square root modes, the AD534 is stable with all
loads up to at least 1000 pF. For critical applications, a small
adjustment to the Z input offset (see Figure 3) improves
accuracy for inputs below 1 V.
UNPRECEDENTED FLEXIBILITY
The precise calibration and differential Z input provide a degree
of flexibility found in no other currently available multiplier.
Standard multiplication, division, squaring, square-rooting
(MDSSR) functions are easily implemented while the restriction
to particular input/output polarities imposed by earlier designs
has been eliminated. Signals can be summed into the output,
with or without gain and with either a positive or negative
sense. Many new modes based on implicit function synthesis
have been made possible, usually requiring only external
passive components. The output can be in the form of a current,
if desired, facilitating such operations as integration.