-~-
ANALOG
(')
'-..
/
InternallyTrimmed
IntegratedCircuitDivider
DEVICES
FEATURES
Pretrimmed to :1:0.5%max Error, 10:1 Denominator
Range (AD535K)
:1:2.0%max Error, 50:1 Denominator Range (AD535K
All Input~ (X, Y and Z) Differential
Low Cost, Monolithic Construction
APPLICATIONS
General Analog Signal Processing
Differential Ratio and Percentage Computations
Precision AGC Loops
Square-Rooting
OBS
"~ .~,
OLE
PRODUCT DESCRIPTION
The AD 535 is a monolithic laser trimmed two-quadrant divider
having performance specifications previously found only in expensive hybrid or modular products. A maximum divider error
of :1:0.5%is guaranteed for the AD535K without any external
trimming over a denominator range of 10: 1, :1:2.0%max error
over a range of 50: 1. A maximum error of :1:1% over the 50: 1
denominator range is guaranteed with the addition of two external trims. The AD535 is the first divider to offer fully differential, high impedance operation on all inputs, including the
z-input, a feature which greatly increases its flexibility and
ease of use. The scale factor is pretrimmed to the standard
value of 10.00; by means of an external resistor, this can be
reduced by any amount down to 3.
The extraordinary versatility and performance of the AD535
recommend it as the first choice in many divider and computational applications. Typical uses include square~rooting, ratio
computation "pin-cushion" correction and AGC loops as illustrated in the applications section of the data sheet. The device
is packaged in a hermetically sealed, 10-pin TO-100 can or 14pin TO-116 DIP and made available in a:1:1% max error version
(]) and a :1:0.5%max error version (K). Both versions are specified for operation over the 0 to +70oC temperature range.
PRODUCT HIGHLIGHTS
1. Laser trimming at the wafer stage enables the AD5 35 to
provide high accuracies without the addition of external
trims (:to.5% max error over a 10:1 denominator range
for the AD535K).
2.
3.
4.
TE
Improved accuracies over a wider denominator range are
possible with only two external trims (:1:0.5%max error
over a 20:1 denominator range for the AD535K).
Differential inputs on the X, Yand Z input terminals
enhance the AD5 35's versatility as a generalized analog
computational circuit.
Monolithic construction permits low cost and, at the
same time, increased reliability.
X2 1
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,
9
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~
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=---=-"
accurate
Devices
of third
ImplicaDevices.
12
NC
-v,
NC
Y1
Y2
Zl
12
Xl
X2
NC
SF
-v,
TO-100
TO-1l6
(TOP VIEW)
Information
furnished
by Analo~J Devices is believed to be
and reliable. However, no responsibility
IS assumed by Analog
for its 'Jse, nor for any infringements
of patents or other rights
parties which may result from its use. No license is granted by
tion or otherwise under any patent or patent rights of Analog
/1
" " " "
1413121110981
OUl
(TOP VIEW)
Route 1 Industrial Park; P.O. Box 280; Norwood, Mass. 02062
Tel: 617/329-4700
TWX: 710/394.6577
West Coast
Mid-West
Texas
213/595~1783
312/894-3300
214/231~5094
-~
----
SPECIFICATIONS
(Vs= :t15V,RL~2kSt, TA= +25°Cunlessotherwise stated)
AD535K
PARAMETER
CONDITIONS
AD535J
TRANSFER FUNCTION
Figure 2
10(Z2-ZI)+YI
(XI -X2)
TOTAL ERRORI
No External Trims, Figure 2
1V~X~lOV,
Z~ Ixi
0.2V~X~lOV,z~lxl
1.0% max
5.0% max
0.5% max
2.0% max
With External Trims, Figure 5
O.5V~X~lOV,
Z~ Ix I
0.2V~X~lOV,
Z~ Ix I
1.0% max
2.0% max
0.5% max
1.0% max
TEMPERATUR~ COEFFICIENT
1V~X~10V,Z~IXI
0.5V~X~10V,
z~IXI
0.2V~X~lOV,Z~IXI
O.Ol%/OCtyp
0.02%fC typ
0.05%fC typ
SUPPLY RELATED
Error
Vs =:l:14V to :l:16V
1V~X~lOV
0.5V~X~lOV
O.2V~X~ 10V
0.1 %/V typ
0.2%/V typ
0.5%/V typ
SQUARE ROOTER
TOTAL ERROR I
No External
OBS
0.4% typ
0.7% typ
X=0.2V, f= 10Hzto 10kHz
X=0.2V
4.5mV rillS typ
f = 50Hz, 20V p-p
60dB min
2.0f.1A max
O.lf.1A typ
10MSt tY£
= 50Hz
VOUT = 0.1 V rillS
70dB typ
1MHz typ
50kHz typ
BANDWIDTH
OUTPUT
AMPLIFIER3
f
Settling Time
Output Impedance
Wide-band Noise
VOUT
OUTPUT
=
CLOAD 1O00pF
Tmin to Tmax
VOUT = 20V p-p
CURRENT
*
*
*
*
20kHz tYE
:I:11 V min
TE
*
*
*
*
*
*
*
*
*
*
*
*
*
Unity Gain, f~ 1kHz
f = 10Hz to 5MHz
f = 10Hz to 10kHz
20V If.1styp
2f.1styp
O.ISt typ
1mV rillS typ
90f.1V rillS typ
Tmin to Tmax, RI = 0
30mA max
*
Quiescent
:l:15V
:l:8V min, :l:18V max
6mA max
*
*
*
= 20V
:1:1%
< POWER SUPPLIES
Rated Performance
Operating
Supply Current
*
*
*
OLE
Open-Loop Gain
Small Signal Gain-Bandwidth
1% Amplitude~rror
Output Voltage Swing
Slew Rate
8
*
*
*
11
1V~Z~lOV
0.2V~Z~10V
NOISE2
INPUT AMPLIFIERS3
CMRR
Bias Current
Offset Current
Differential Resistance
Trims, Figure
*
8
NOTES:
.Specifications
same as ADS 35J.
1 Figures are given as a percent of full scale (i.e. 1.0%
2 Noise may be reduced as shown in Figure 14.
3 See Figure 1 for definition of section.
Specifications
subject
to change without
= 100mV).
notice.
8
-2-
PHYSICAL DIMENSIONS
Dimensions
shown in inches and (mm).
VOUT
TO-116
I--
O.032R"'~
~
I
--1
~
009512.411
0.75111908)~
o:736T18~69f
-
l--.l
OBS
tmfflf
i ~U
0035
10.891
l
0.032
10811
~:~I
i
!i
u
_II
r-- ,r--
0.05
1127)
0.018
1046)
(XI-XZ)(YI-VOUT)
SF
- (ZI
- Zz)
]
x, Y, Z = input voltages
SF = scale factor, pretrimmed to 10.00V but adjustable
by the user down to 3V.
In most cases the open loop gain can be regarded as infinite
and SF will be 10V. Dividing both sides of the equation by A
and solving the VOUT, we get...
(Zz - Zd
VOUT = 10V (Xl - Xz) + YI
[[1""
"'f
.-
[
where A = open loop gain of output amplifier, typically 70dB
at dc
0.472111991--I
I---
=A
.H
+vs
SF
0.1
12541
TO-lOO
-VS
OLE
v,
X,
X2
V2
TRANSLINEAR
MUL TlPLIER
ELEMENT
TE
z,
Z2
OUT
HIGH GAIN
OUTPUT
AMPLIFIER
Figure 1. AD535 Functional Block Diagram
ABSOLUTE
SOURCES OF ERROR
Divider error is specified as a percent of full scale (i.e. 10.00V)
and consists primarily of the effects of X, Y and Z offsets and
scale factor (which are trimmable) as shown in the generalized
equation....
MAXIMUM RATINGS
Supply Voltage
Internal Power Dissipation
Output Short-Circuit
to Ground
Input Voltages, XI, XZ, Y I, Y Z, ZI , Zz
Rated Operating Temp Range
Storage Temp Range
Lead Temp, 60s soldering
:t18V
500mW
Indefinite
:tVs
0 to +70°C
-65°C to +l50°C
+300°C
VOUT
25-99
100-999
AD535JH
$26.00
$21.00
$16.00
AD535JD
$30.00
$25.00
$20.00
AD535KH
$36.00
$30.00
$24.00
AD535KD
$41.00
$35.00
$29.00
+ .6.SF)
[
(Zz - ZI ) + Zos
(XI -Xz)+Xos
+ Y I + Yos
Overall accuracy of the AD5 35 can be significantly improved
by nulling out X and Z offset as described in the applications
sections. Figure 13 illustrates a factor of 2 improvement in
accuracy with the addition of these external trims. The remaining errors stem primarily from scale factor error and Y offsets which can be trimmed out as shown in Figure 6.
FUNCTIONAL DESCRIPTION
Figure 1 is a functional block diagram of the AD5 35. Inputs
are converted to differential currents by three identical voltage
to current converters, each trimmed for zero offset. The product
of the X and Y currents is generated by a multiplier cell using
Gilbert's trans linear technique with an internal scaling voltage.
Figure 14 illustrates the bandwidth and noise relationships
versus denominator voltage. Whereas noise increases with
decreasing denominator, bandwidth decreases, the net result
given by the expression...
EnoUT (wideband)
The difference between XY (SF and Z is applied to the high gain
output amplifier. The transfer function can then be expressed...
=~
it:O)
-3-
--
]
Note especially that divider error is inversely proportional to
X, that is, the error increases rapidly with decreasing denominator values. Hence, the AD535 divider error is specified over
several denominator ranges on page 2. (See also Figure 12,
AD535 Total Error as a function of denominator values.)
PRICING
1-24
=(SF
-
-------
mV rms
External filtering can be added to limit output voltage noise
even further. In this case...
EnOUT (B.W. externally limited) = 0.9..Jf
mV rms
~ ~O)
where f
= bandwidth
in MHz of an external
filter whose band-
width is less than the noise bandwidth of the ADS 35. Table 1
provides calculated values of the typical output voltage noise,
both filtered and unfiltered for several denominator values.
Noise
10Hz to 5MHz
X
0.2V
O.5V
IV
10V
8.9mV
5.6mV
4.0mV
1.3mV
Noise Limited by
External Filtenng
10Hz to 10kHz
Negative denominator inputs are handled as shown in Figure 4.
Note that in either configuration, operation is limited to two
quadrants (i.e. Z is bipolar, X is unipolar).
A factor of two improvements in accuracy is possible by
trimming the X and Z offsets as illustrated in Figure 5. To
trim, set X to the smallest denominator value for which accurate computation is required (i.e., X = 0.2V). With Z = 0,
adjust the Zo trim for VOUT = O. Next, adjust the Xc trim
for the best compromise
Z = -X (VOUT = -laY).
= +X
(VOUT
= +lOV)
and
compromise at Z = +X, Z = -X and Z = O. The remaining error
(Figure 13) consists primarily of scale factor error, output
offset and an irreducible nonlinearity component.
4.5mV rms
1.8mV rms
0.9mV rms
0.09mV rms
rms
rms
rms
rms
when Z
Finally, readjust Zo for the best
+15V
OBS
X,N
50k
lOOk
Xo
ADJ.
Table 1. AD535Calculated Voltage Noise
APPLlCA TIONS
Figure 2 shows the standard divider connection without external trims. The denominator X, is restricted to positive
values in this configuration. X, Y and Z inputs are differentia]
with high (80dB typical) CMRR permitting the application of
differential signals on X and Z (see Figure 3).
VOUT
lOOk
OLE
-15V
50k
Za
ADJ.
TE
Figure 5. Precision Divider Using Two Trims
VaUT"
'~Z
IX MUST
BE
POSiTlVE(
In certain applications, the user may elect to adjust SF for
values between 10.00 and 3 by connecting an external resistor
in series with a potentiometer between SF and -Vs. The approximate value of the total resistance for a given value of
SF is given by the relationship:
SF
RSF = 5.4K 10 - SF
-15V
Figure2. Divider Without External Trims
Due to device tolerances, allowance should be made to vary
RSF :1:25%using the potentiometer. Note that the peak signal
is always limited to 1.25 SF (i.e. j:5V for SF = 4).
OUT
- 10 IZ, - z, (
---
8)
--0
.
Z~
VOUT- -~;I
x, - x, MUSTBE
POSITIVE
-b
1i
'VI
Scale factor and output offset error can be minimized utilizing
the four trim circuit of Figure 6. Adjustment is as follows:
I
j
-15V
The scale factor may also be adjusted using a feedback attenuator between VOUT and Y2 as indicated in Figure 6. The input
signal range is unaffected using this scheme.
1.
Figure 3. Differential Divider Connection
2.
+15V
Apply X = +0.2V (or the smallest required denominator
value), Z = 0 and adjust Zo for VOUT = O.
Apply X = 0.2V. Then adjust the Xo trim for the best
compromise
X
INPUT
VOUT
Z
INPUT
102
-x-
(X MUST BE
NEGATIVE!
3.
4.
5.
6.
Figure 4. Divider Connection for Negative X Inputs
-4-
when Z
= +X
(VOUT
= +lOV)
and Z
=
-x (VOUT = -lOV.)
Apply X = +lOV, Z = 0 and adjust Yo forVOUT = U.
Apply X = +lOV. Then adjust the scale factor (SF) trim
for the best compromise when Z = +X (VOUT = +lOV)
and Z = -x (VOUT= -lOV).
Repeat steps 1 and 2.
Apply X = 0.2V. Then adjust the Z trim for the best
compromise when Z = X (VOUT = +lOV), Z = 0 (VOUT =
0) and Z = -X (VOUT = -laY).
+15V
In typical applications L (expressed in voltage) is roughly equal
to full scale VIH or VIV. The result is that the expression,
50k
.v(VIH 2 + VIV 2 + L 2 ),
varies less than 2: lover
the full range
of values of VIH and VIV.
+15V
VaUT
Major sources of divider error associated with small denominator values can thereby the minimized.
+15V
lOOk
Ya
ADJ.
50k
z
V,H
-15V
50k
SCALE
FACTOR
ADJ.
-15V
1k
x DIVIDER
20k
VOH
Z INPUT
TO
CRT
lOOk
V,V
Z
AD535
DIVIDER
'O;r
OBS
VOV
}
DISPLAY
X
.15V
Figure 6. Precision Divider with Four External Adjustments
These trim adjustments can be made either by using two calibrated voltage sources and a DVM, or by using a differential
scope, a low frequency generator, a voltage source and a
precision attenuator. As shown in Figure 7, the differential
scope
subtracts
onl y errors.
Set the
the expected
attenuation ideal
to oujfut
-
OLE
and thus displays
10'
DIVIDER
UNDER
TEST
TE
Figure 8. Pin-Cushion Corrector
Figure 9 shows an AGC loop using an AD535 divider, The
AD535 lends itself naturally in this application since it is configured to provide gain rather than loss. Overall gain varies
from 1 to 00 as the denominator is servoed to maintain VauT
at a constant level.
INPUT
SCOP[
VaUT
(CONSTANT ,msl
AD536
'ms/dc
CONVERTER
Figure 7. Alternate Trim Adjustment
PIN-CUSHION
Set-Up
(FIXED OR
ADJUSTABLEI
CORRECTION
Figure 9. AGC Loop Using the AD536 rms/dc Converter
A pin-cushion corrector eliminates the distortion caused by
flat screen CRT tubes. The correction equations are:
as a Detector
Figure 10 shows a method for obtaining the time averageas
defined by:
1 T
X=T [ Xdt
VIH
VaH
J
and
VIV
Vav
V
where:
VIH2 + VIV2 + L2
I
VIH
2
+ VIV
2
+ L
where T is the time interval over which the average is to be
taken. Conventional techniques typically provide only a crude
approximation to the true time average, and furthermore, require a fixed'time interval before the averagecan be taken. In
Figure 10, the AD535 is used to divide the integrator output
by the ramp generator output. Since the ramp is proportional
to time, the integrator is divided by the time interval, thus
allowing continuous, true time processing of signals over intervals varying by as much as 50:1.
2
VaH and Vav are the horizontal and vertical output
signals, respectively.
VIH and VIV are the horizontal and vertical input
signals, respectively.
L is the length of the CRT tube.
-5-
10%
V,N
z
INTEGRATOR
I
=
VOUT
AO535
-;-J~IN
x
I
I
I
dt
..
&
<5
RESET
~
B
'"
~
RAMP
GENERA TOR
1%
"
I
'0
~
Figure 10. Time Average Computation
Circuit
VOUT
YPICAL
"
OBS
Figure 11. Square Rooter
I---t-t-t
,--,-~-
f
~~
'
I
--~
I
--+
TYPICAL
i
II
I
,
II Iii!
I
:,
i
i
-
~
i
'--~-+-
I
I
T
ii
,I
I
---1
I
TRIMS..><
vV
V
co
,....
-co
I
co
I
&3
(D
<5
L-+-
'
,
i
.
I
TI
!
,
i
I
I
I I
I II
100~V
0_1
10
Trims at 25°C
BANDWIDTH
1.0
DENOMINATOR
IN VOLTS
IN VOLTS
with No External
10
TE
-
TYPICA~ AD535K
I
1
IN VOLTS
OLE
AD5 35J
TYPICAL
0.1
I
II
1
AD535Error
4
.1-
TYPICAL
FOR
AD534K
WITH
2 EXT. TRIMS
OUTPUT
NOISE.rms
J--t-jI
I
MAX AD535J i
DENOMINATOR
Figure 12.
Ii
I
",
AD534K
"ii'
"
I
1l--f~
-l
Ii!
'II
I
0_1%
0.1
I
1-r-j-
';
-+H--
,-,---L+~---
*~
~
I
AD535 ERROR WITH NO EXTERNAL TRIMS
'--i
WITH
Figure 13. .Errors with External
INPUT
I
t::
DENOMINATOR
NOTE Z MUST BE POSITIVE
IN CIRCUIT SHOWN, IF DIODE
IS REVERSED, THEN Z MUST
BE NEGATIVE
I
I I I
I
0.01
-
I
c
_:SK
I
(MUST BE
PROVIOED)
,
,
10%
g
RL
~
-15V
MAXSPEC
FORAD535J
WITHTWOEXT.TRIMS
,,
I
a:
a:
w
:#-
=.JiOZ
.
TYPICALFORAD535J
I
~ 0_1%
'
l"'-l
r-----WITH2 EXT.TRIMS
~
+15V
i
I
""',
I
*-
I
100kHz
10kHz
(
-
Figure 14. -3dB Bandwidth and Noise vs. Denominator
Trims
<
c,
,
(
L
t
'"",-
-6-