8 Bit Monolithic
Multiplying
0/ A Converter
FEATURES
ImprovedRepl~C8m~ntfor Industry Standard 1408/1508
ImprovedSettling Time: 250ns typ
ImprovedLinearity: :to.1% Accuracy GuaranteedOver
TemperatureRange(-9 Grade)
HighOutput Voltage Compliance: +O.5V to -5.0V
LoWpower Consumption: 157mW typ
HighSpeed2.Quadrant Multiplying Input: 4.0mA/lls
SlewRate
SingleChip Monolithic Construction
Hermetic16 Pin Ceramic DIP
LoWCost
OBS
OLE
PRODUCTDESCRIPTION
TheAD1408 and AD1S08 are low cost monolithic integrated
circUit8-bit multiplying digital-to-analog converters, consisting
ofmatched bipolar switches, a precision resistor netWork and a
controlamplifier. The single chip is mounted in a hermetically
sealedceramic 16 lead dual-in-line package.
PRODUCT HIGHLIGHTS
1. Monolithic IC construction makes the AD 1408/AD1S08 an
optimum choice for applications where low cost is a major
consideration.
Advancedcircuit design and precision processing techniques
resultin significant performance advantages over older industry standard 1408/1S08 devices. The maximum linearity error
overthe specified operating temperatUre range is guaranteed
to be less than :t%LSB (-9 grade) while settling time to :t'hLSB
isreduced to 2S0ns. typo The temperature coefficient of gain
istypically 2Oppm/C and monotonicity is guaranteed over
the entire operating temperatUre range.
TheAD1408/AD1S08 is recommended for all low-cost 8-bit
DACrequirements; it is also suitable for upgrading overall
performance where older, less accurate and slower 14O8/1S08
deviceshave been designed in. The AD14O8 series is specified
for operation over the 0 to +7SoC temperature range, the
ADlS08 series for operation over the entire militaty temperatUrerange of -SSoC to +12SoC.
3. Versatile design configuration allows voltage or current outputs, variable or fixed reference inputs, CMOS or TTL
logic compatibility and a wide choice of accuracy and temperatUre range specifications.
TE
2. The AD1408/AD1S08 directly replaces other devices of
this type.
4. Accuracies within :t%LSB allow performance improvement
of older applications without redesign.
S. Faster settling time (2SOns typ) permits use in higher speed
applications.
6. Low power consumption improves stability and reduces
warm-up time.
7. The AD1408/AD1S08 multiplies in tWo quadrants when a
varying reference voltage is applied. When multiplication is
not required, a fixed reference is used.
8. The AD1408/AD1S08 is available in chip form; please consult factory for details.
9. The device is packaged in a hermetically-sealed ceramic 16
lead dual-in-line package. Processing to MIL-STD-883 level
B is available.
D/A CONVERTERS 295
SPECIFICA
JIUNS (typical@+25°e andVee = +5.0Vdc, VEE= -15V deunlessotherwisenoted)
MAXIMUM RATINGS
RATING
POWERSUPPLYVOLTAGE
SYMBOL
VALUE
UNIT
Vee
VEE
+5.5
-16.5
V de
V de
Vs thru V12
+5.5,0
V de
Vo
+0.5, -5.2
Vde
114
5.0
mA
V14' VIS
Vee, VEE
Vde
Po
1000
6.7
mW
mWt"C
OPERATING TEMPERATURE RANGE
ADI408 Series
ADlS08 Series
TA
TA
0 to +75
-55 to +125
'c
'c
STORAGE TEMPERATURE RANGE
TG
-6S to +150
'c
DIGITAL INPUT VOLTAGE
APPLIED OUTPUT VOLTAGE
REFERENCE
CURRENT
REFERENCE AMPLIFIER INPUTS
POWER DISSIPATION
(Package Limitation)
Derate: above TA
= +2S.C
OBS
ELECTRICAL CHARACTERISTICS
(Vee
= +S.OVdc:,VEE= -lSV
ADI408
Series:
TA
= 0 to
dc:,
+7S.C
VREF
unfte
otherwise
All digital
SYMBOL
(Error Relative to Full Sc:ale '0)
ADlS08-9, AD1408-9
ADlS08-8, ADI408-8
AD1408-7
SETTLINGTIME
to Within 1I2LSB [Inc:ludesTpLH]
(TA =+2S.C)
E.
E.
E.
ts
PROPAGATION DELAY TIME
TA = +2S.C
OUTPUT FULL SCALE CURRENT DRIFT
DIGITALINPUTWGIC LEVELS(MSB)
High Levc:l,Logic:"I"
Low Level,Logic "0"
DIGITALINPUTCURRENT(MSB)
High Levc:l,VIN= S.OV
Low Levc:l, VIL = 0.8V
REFERENCEINPUTBIASCURRENT
(Pin IS)
OUTPUTCURRENTRANGE
VEE = -S.OV
VEE=-6.0V to -ISV
OUTPUTCURRENT
R14 = l00on
OUTPUTCURRENT
(All BitSLow)
OUTPUTVOLTAGECOMPLIANCE
-(E, "0.19%
OLE
noted.
RELATIVE ACCURACY
=2.000V,
...
.. 2.OmA,AD1508 Series: TA= -SS C to +12S C
CHARACTERISTIC
VREF
at TA
TpLH ,TpHL
TClo
MIN
TYP
MAX
UNIT
-
-
-
-
-
-
:to.l0
:to.19
:to.39
%
%
%
-
2S0
-
ns
30
100
ns
-
-20
-
ppmrc
2.0
-
-
Vde
Vde
-
0
-0.4
0.04
-0.8
mA
mA
-
-1.0
-3.0
p.A.
'oR
'oR
0
0
2.0
2.0
2.1
4.2
mA
mA
'0
1.9
1.99
2.1
mA
'0 (min)
-
0
4.0
p.A.
-
-
-
-0.6, +0.5
-S.O, +O.S
Vde
Vde
4.0
-
mAills
-
O.S
2.7
p.A./V
-
+9
-7.S
+14
-13
mA
mA
+4.S
-4.S
+S.O
-IS
+S.S
-16.S
Vde
V de
-
82
IS7
13S
26S
mW
mW
-
70
132
-
mW
mW
IJH
IlL
lIS
Va
Va
SRIREF
PSS'o
Ice
lEE
-
POWERSUPPLYVOLTAGERANGE
= +2S.C)
VeeR
VEER
POWERDISSIPATION
All BitSLow
VEE = -S.OVde
VEE= -ISV de
Po
Po
All BitS High
VEE =-5.0V dc:
VEE -15V de
Po
Po
=
spccif"JCatioassubject to elwlF without notice.
296 D/A CONVERTERS
TE
-
0.8
OUTPUT CURRENT POWER SUPPLY
SENSITIVITY
POWERSUPPLYCURRENT
(All BitSLow)
inputS at high logic: leve1.)
-
VJH
VIL
= +2S.C)
VEE= -SV
VEEbelow-l0V
REFERENCECURRENTSLEWRATE
(TA
-
-
GTHEAD1408/lS08
#"",(11J\JIIplifierDriveand Compensation
16 COMPEN
~
f~s
d 2b are the connection diagrams for using the
Z~1508 in basic voltage output modes. In Figure 2a, a
tJJl4f)8/f rencevoltage, VREF'is converted to a current by
~ifie rei:. This reference current determines the scale
~or R the output current such that the full scale output
i,&torfO(1/256)
less than the reference current. R15 provides
61(,58 t compensation to the reference control amplifier
biJ5cU~'~etemperatUre drift; it is nominally equal to R14
toIIIj/I~~tneedn't be a stable precision resistor. This conptbOU~on
a negative output voltage across RL and
ratJ develops
.'
V
'9- ireSa pOSluve REF'
rei!" ative VREF is to be used, connections to the reference
If'II~ amplifier must be reversed as shown in Figure 2b. This
coII~~alsodelivers a negative output voltage, but presents
'~
impedance to the reference source. The negative VREF
.
e at least 4 volts above the VEE supply.
lIIustb
quadrant multiplication may be performed by applying
r;';olar ac signal as the reference as long as pin 14 is positive
~tive to pin 15 (reference current must flow into pin 14). If
theat:reference is applied to pin 14 through R14, a negative
lcageequal to the negative peak of the ac reference must be
;plied through RlS to pin IS; ifthe ac reference is applied to
iJ115through RlS, a positive voltage equal to the positive
~ofthe
ac reference must be applied through R14 to pin 14.
Whena dc reference is used, capacitive bypass from reference
toground will improve noise rejection.
Thecompensation capacitor, C, provides proper phase margin
forthe reference control amplifier. As R14 is increased, the
dosed-loopgain of the amplifier is decreased, therefore C must
beincreased. For R14 = 1.0kO, 2.SkO and S.OkO,minimum
valuesof capacitance are 1SpF, 37pF and 7SpF respectively.
Cmaybe tied to either VEEor ground, but tying it to VEE
increasesnegative supply noise rejection. If the reference is
drivenby a high-impedance current source, heavy compensationof the amplifier is required; this causes a reduction in
overallbandwidth.
OBS
15 VREF (-)
14 VREF (+1
13 Vcc
12 AS ILSSI
11 A7
10 A6
9AS
TOP VIEW
Figure 1. Pin Connections
Vcc
OLE
13
A1 (MSSI
VREF 1+1
14
1+1 VREF J"'L
R14
VREF I-I
15
4
-
10
AS (LSS)
R15 ~
TE
RL
"l.J'"
~
R14-R15
C
(SEE TEXT)
VEE
a. Connections for Use with Positive Reference
Vcc
I
.
Output Current Range
Thenominal value for output current range is 0 to 1.992mA
asdetermined by a 2mA reference current. If VEE is more
negativethan -7.0 voltS, this range may be increased to a maximumof 0 to 4.2mA. An increase in speed may be realized at
increasedoutput current levels, but power consumption will
increase,possibly causing small shifts in linearity.
Pin 1, range control, may be grounded or unconnected. Although other older devices of this type require different
terminations for various applications, the AD 1408/ AD 1S08
compensates automatically. This pin is not connected internally,therefore any previously installed connections will
be tolerated.
Output Vol.
Range
Thevoltage on pin 4 is resmcted to a +O.S to -0.6 volt range
when VEE
= -SV.
When VEE is more negative than -10 volts,
this range is extended to +O.S to -S.O voltS. If the current into
pin 14 is 2mA (full-scale output current = 1.992mA), a 2.SkO
resistor betWeen the output, pin 4, and ground will provide a
0 to -4.980 volt full-scale. If ~ exceeds soon however, the
settling time of the device is increased.
13
A1
IMSS)
VREF 1+1
14
~
VREF I-I
15
-VREF 1..I
R15
4
A6
C
(SEE TEXT
-
10
ILSSI
~
"l.J'"
~
R14-R15
I
VEE
b. Connections for Use with Negative Reference
Figure 2. Basic Connections
D/A CONVERTERS 297
~
Voltage Output
A low impedance voltage output may be derived from the output current of the AD 1408/ADI508 by using an output amplifier as shown in Figure 3. The output current 10 flows in Ro
to create a positiv~oingvoltage
range at the output of amplifier
AI. Ro may be chosen for the desired range of output voltage;
the complete circuit transfer function is given in Figure 3.
"-
VREF (-)
A1 CMSBI::J6
A2
8
VREF C+I
14
t5V
7
8
AD1408/
M:'
.....
A7
A8 (LSBI
CaMP
Calibration for Unipolar Outputs (No RsP)
OBS
1.21ikf!
.. 6.CIOItri
-16pF
- 2.fiOkn
Ro
C
Rs..
If a bipolar output voltage range is desired, Rsp, shown dotted,
must be installed. Its purpose is to provide an offset equal to
one-half of full-scale at the output of AI. The procedure for
calibrating the circuit of Figure 3 is as follows:
1. With all bits "OFF", adjust the Al null-pot, Rl, for
VOUT = O.OOV.
.
- RtlEF
"-
11
12
4
Your
I
+1&V
.
C
CSEETExn"
2. With all bits "ON", adjust RREF for VOUT = (Nominal
lLSB =+9.961 volts
Full Scale)
-
o.MN'='
-15V
2OOk
+16V
Calibration for Bipolar Outputs (Rsp installed, R 1 not
required)
y
1. With all bits "OFF", adjust Rsp for VOUT = -F.S. =
-5.000 volts
ADJUST VREF, R,.EFORRo so THAT WITH ALL DIGITAL INPUTS
AT LOGIC "1", VOUT- 9.961 VOLTS:
2. With Bit 1 (MSB) "ON", and all other Bits "OFF",
adjust RREF for VOUT = O.OOOV.
YOUT
A1
ua
A2
KJ
AA
AS
A6
A7
AS
.~CR
R,.EF
0
[
I ~+E+~+..M.+~+~+.B...+~
2
4
8
18
OLE
3. With all bits "ON", verify that EoUT = +5.000VlLSB = 4.961V.
MSB
OUT
--
f
2.6
1
1
1
(6knl -+-+-+-+-+-+-+1.25kS1
2
4
8
1
18
32
84
1
32
128
1
84
1
128
]
258
1
258
]-9.981VOLTS
Figure 3. Typical Connection Diagram, AD 1408/AD 1508,
Voltage Output, Fixed Reference
TE
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
16-PIN DUAL-IN-LINE
VREF 1+)
a.14
Vcc
=:~{~~~~::J#:;
It
16
L
VREF(-)
MAX
COMPEN
3
AS AA KJ
LSB
AS.8.
Gr........
mlll.lrU
"f:
~0.381
~
~JtJ..::::::
0.01410.38:
ADl408/AD1508
MODEL
LIlliLLIT.LIiIIr...alla
COMP
I..
GND
0.096 (2.441
THE AD1408fAD1508
IS AVAILABLE
IN CHIP FORM
GUARANTEED
TO -7 LEVEL PERFORMANCE.
CONSULT FACTORY FOR APPLICATION
AND
PRICING DETAILS.
Figure 5. Chip Dimensions and Pad Layout.
Dimensions shown in inches and (mm).
298 D/A CONVERTERS
ACCURACY
(:1:%F.5.1
10
AD1408-7D
AD1408-8D
AD 1408-9D
AD1508-8D
AD 1508-9D
AD 1508-8DI
883B
AD1508-9DI
883B
..
I.
0.306 (7.771
TEMP.
RANGE
(OCI
0.39
0.19
0.10
0.19
0.10
0 to +75.
0 to +75
Oto+75
-55 to +125
-55 to +125
0.19
-55 to +125
0.10
-55 to +125
\\
-I
0.2!M (7.471
ORDERING GUIDE
A1
MSB
Vcc
0.074
. .10612.671
...~,-1
A2
' ,:R
0.03510.891
15"
"
Figure 4. Simplified Block Diagram
I
0.725 11...21
O"J2,:'~
~~~
VEE
A7 A8
0.825 120.961
I
-
O.o1SfO.JIJ