AD1408_15 Datasheet, PDF (4/4 Pages) Analog Devices – 8 Bit Monolithic Multiplying 0/A Converter

~
Voltage Output
A low impedance voltage output may be derived from the out-
put current of the AD 1408/ADI508 by using an output ampli-
fier as shown in Figure 3. The output current 10 flows in Ro
VREF (-)
. - "- RtlEF 1.21ikf!
Ro .. 6.CIOItri
C -16pF
Rs.. - 2.fiOkn
"-
to create a positiv~oingvoltage range at the output of amplifier
AI. Ro may be chosen for the desired range of output voltage;
A1 CMAS2BI::J6 8
VREF C+I
14
t5V
7
the complete circuit transfer function is given in Figure 3.
If a bipolar output voltage range is desired, Rsp, shown dotted,
8 AD1408/
must be installed. Its purpose is to provide an offset equal to
M:' .....
one-half of full-scale at the output of AI. The procedure for
calibrating the circuit of Figure 3 is as follows:
A7 11
A8 (LSBI 12
4_I
Your
Calibration for Unipolar Outputs (No RsP)
CaMP
+1&V
1. With all bits "OFF", adjust the Al null-pot, Rl, for
VOUT = O.OOV.
C^.
CSEETExn"
2. With all bits "ON", adjust RREF for VOUT = (Nominal
- = Full Scale) lLSB +9.961 volts
Calibration for Bipolar Outputs (Rsp installed, R 1 not
required)
[ ] 1. With all bits "OFF", adjust Rsp for VOUT = -F.S. =
-5.000 volts
O _{-- 2. With Bit 1 (MSB) "ON", and all other Bits "OFF",}
B ^{f ]} _{adjust RREF for VOUT = O.OOOV.}
S ^{3. With all bits "ON", verify that EoUT = +5.000V-}
lLSB = 4.961V.
OL _MSB
ua
ETE ^{A1 A2 KJ AA AS A6 A7 AS}
o.MN_'='
-15V
2OOk
+16V
y .~CR I ~+E+~+..M.+~+~+.B...+~
OUT R,.EF 0 2
4
8 18 32 84 128 258
ADJUST VREF, R,.EFORRo so THAT WITH ALL DIGITAL INPUTS
AT LOGIC "1", VOUT- 9.961 VOLTS:
Y_OUT
12.2.65kS1^(6knl
-+¹₂-+-+-¹₄+-+-+¹-₈+-
1
18
1
32
1
84
1
128
1
258
-9.981VOLTS
Figure 3. Typical Connection Diagram, AD 1408/AD 1508,
Voltage Output, Fixed Reference
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
16-PIN DUAL-IN-LINE
VRE_aF_.-1+)
14
16
VREF(-)
Vcc
COMPEN
3
VEE
Figure 4. Simplified Block Diagram
A7 A8 AS AA KJ A2
G^Lr^SVA.^Bc.^Sc.^.8.^.....
AM1 SB
0.074 mlll.lrU LIllLiLIT.LIiIIr...alla 10
"f:
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
=:~{~~~~::J#:;
L
I-
I
0.825 120.961
0.725 11...21
t
I
MAX
O"J2,~:'~~~
. "
.10612.671
...~,-1
0.03510.891
15"
R ~0.381
~JtJ^~..::::^':: ^..,:I. -_I - _0.01410.38:
\\ O.o1SfO.JIJ
0.2!M (7.471
0.306 (7.771
ADl408/AD1508 ORDERING GUIDE
MODEL
TEMP.
ACCURACY RANGE
(:1:%F.5.1 (OCI
AD1408-7D
AD1408-8D
AD 1408-9D
AD1508-8D
AD 1508-9D
AD 1508-8DI
883B
AD1508-9DI
883B
0.39 0 to +75.
0.19 0 to +75
0.10 Oto+75
0.19 -55 to +125
0.10 -55 to +125
0.19 -55 to +125
0.10 -55 to +125