ON MC1408-8DG 8â bit multiplying d/a converter Datasheet

MC1408−8
8−bit Multiplying D/A
Converter
The MC1408−8 is an 8−bit monolithic digital−to−analog converter
which provides high−speed performance with low cost. It is designed
for use where the output current is a linear product of an 8−bit digital
word and an analog reference voltage.
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Features
•
•
•
•
•
•
•
MARKING DIAGRAMS
Fast Settling Time: 70 ns (typ)
Relative Accuracy ±0.19% (max error)
Non−inverting Digital Inputs are TTL and CMOS Compatible
High−speed Multiplying Rate 4.0 mA/ms (Input Slew)
Output Voltage Swing +0.5 V to −5.0 V
Standard Supply Voltages +5.0 V and −5.0 V to −15 V
Pb−Free Packages are Available*
Applications
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
16
1
1
16
1
Tracking A−to−D Converters
2 1/2−Digit Panel Meters and DVMs
Waveform Synthesis
Sample−and−Hold
Peak Detector
Programmable Gain and Attenuation
CRT Character Generation
Audio Digitizing and Decoding
Programmable Power Supplies
Analog−Digital Multiplication
Digital−Digital Multiplication
Analog−Digital Division
Digital Addition and Subtraction
Speech Compression and Expansion
Stepping Motor Drive Modems
Servo Motor and Pen Drivers
MC1408−8DG
AWLYWW
SOIC−16
D SUFFIX
CASE 751B
MC1408−8N
AWLYYWWG
PDIP−16
N SUFFIX
CASE 648
1
A
WL
YY, Y
WW
G
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
PIN CONNECTIONS
N Package
NC
1
16
COMPEN
GND
2
15
VREF(−)
VEE
3
14
VREF(+)
IO
4
13
VCC
MSB A1
5
12
A8 LSB
A2
6
11
A7
A3
A4
7
10
A6
8
9
A5
D Package*
16
A8 LSB
2
15
A7
VREF(−) 3
14
A6
COMPEN
4
13
A5
NC
5
12
A4
GND
6
11
A3
VEE 7
10
A2
IO
9
A1 MSB
VCC 1
VREF(+)
8
(Top View)
*SO and non−standard pinouts.
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
© Semiconductor Components Industries, LLC, 2006
May, 2006 − Rev. 2
1
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 8 of this data sheet.
Publication Order Number:
MC1408−8/D
MC1408−8
MSB
A1
A2
5
6
A3
A4
7
8
A5
A6
9
LSB
A8
A7
10
11
12
IO
4
CURRENT SWITCHES
BIAS
CURRENT
R-2R LADDER
VREF
(+)
14
REFERENCE
CURRENT
AMPLIFIER
15
(−)
VREF
2
GND
13
VCC
16
COMPEN
VEE
3
NPN CURRENT SOURCE PAIR
Figure 1. Block Diagram
PIN FUNCTION DESCRIPTION
Pin
N Package / D Package
Symbol
1/5
NC
2/6
GND
Ground
3/7
VEE
Negative Power Supply
4/8
Io
Output Current
5/9
A1
Output 1, Most Significant Bit (MSB)
6/10
A2
Output 2
7/11
A3
Output 3
8/12
A4
Output 4
Description
No Connect
9/13
A5
Output 5
10/14
A6
Output 6
11/15
A7
Output 7
12/16
A8
Output 8, Least Significant Bit (LSB)
13/1
VCC
14/2
VREF(+)
Positive Reference Voltage
15/3
VREF(−)
Negative Reference Voltage
16/4
COMPEN
Compensator Capacitor Pin
Positive Power Supply
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2
MC1408−8
MAXIMUM RATINGS
Symbol
Value
Unit
Positive Power Supply Voltage
Rating
VCC
+5.5
V
Negative Power Supply Voltage
VEE
−16.5
V
V5 − V12
0 to VCC
V
Applied Output Voltage
VO
−5.2 to +18
V
Reference Current
I14
5.0
mA
V14, V15
VEE to VCC
Digital Input Voltage
Reference Amplifier Inputs
Maximum Power Dissipation, Tamb = 25°C (still−air) (Note 1)
N Package
D Package
PD
mW
1450
1080
°C/W
Thermal Resistance, Junction−to−Ambient
N Package
D Package
RqJA
Operating Temperature Range
Tamb
0 to +75
°C
Operating Junction Temperature
TJ
150
°C
Storage Temperature Range
Tstg
−65 to +150
°C
Lead Soldering Temperature (10 sec)
Tsld
+230
°C
75
105
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. Derate above 25°C, at the following rates:
N package at 13.3 mW/°C;
D package at 9.5 mW/°C.
IO OUTPUT CURRENT (mA)
TYPICAL PERFORMANCE CHARACTERISTICS
0
1.0
2.0
(00000000)INPUT DIGITAL WORD(11111111)
Figure 2. D−to−A Transfer Characteristics
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3
MC1408−8
DC ELECTRICAL CHARACTERISTICS (Pin 3 must be 3.0 V more negative than the potential to which R15 is returned. VCC
+5.0 VDC, VEE = −15 VDC, VREF/R14 = 2.0 mA unless otherwise specified. Tamb = 0°C to 75°C, unless otherwise noted.)
Characteristic
Test Conditions
Symbol
Min
Typ
Relative Accuracy
Error relative to full−scale IO,
Figure 5
Er
Settling Time (Note 2)
To within 1/2 LSB, includes tPLH;
Tamb = +25°C, Figure 6
tS
70
tPLH
tPHL
35
TCIO
−20
Propagation Delay Time
Low−to−High
High−to−Low
Digital Input Logic Level (MSB)
High
Low
Figure 7
Digital Input Current (MSB)
High
Low
Figure 7
VIH = 5.0 V
VIL = 0.8 V
Reference Input Bias Current
Output Current Range
Off−State
Output Voltage Compliance
Unit
±0.19
%
ns
ns
Tamb = +25°C, Figure 6
Output Full−scale Current Drift
Output Current
Max
100
ppm/°C
VDC
VIH
VIL
2.0
0.8
mA
IIH
IIL
0
−0.4
0.04
−0.8
Pin 15, Figure 7
I15
−1.0
−5.0
Figure 7
VEE = −5.0 V
VEE = −7.0 V to −15 V
IOR
Figure 7
VREF = 2.000 V, R14 = 1000 W
All bits low
IO
Reference Current Slew Rate
Figure 8
Output Current Power Supply
Sensitivity
IREF = 1.0 mA
Power Supply Current
Positive
Negative
All bits low, Figure 7
0
0
2.0
2.0
2.1
4.2
1.9
1.99
0
2.1
4.0
IO(min)
Er ≤ 0.19%.0 at
TA = +25°C, Figure 7
VEE = −5.0 V
VEE below −10 V
mA
mA
VO
mA
mA
VDC
−0.6 +10
−5.5, +10
−0.55, +0.5
−5.0, +0.5
SRIREF
8.0
PSRR(−)
0.5
2.7
ICC
IEE
+2.5
−6.5
+22
−13
+5.0
−15
+5.5
−16.5
34
110
170
305
mA/ms
mA/V
mA
Power Supply Voltage Range
Positive
Negative
Tamb = +25°C, Figure 7
Power Dissipation
All bits low, Figure 7
VEE = −5.0 VDC
VEE = −15.0 VDC
VCCR
VEER
VDC
+4.5
−4.5
PD
2. All bits switched.
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4
mW
MC1408−8
Circuit Description
The MC1408−8 consists of a reference current amplifier,
an R−2R ladder, and 8 high−speed current switches. For
many applications, only a reference resistor and reference
voltage need be added.
The switches are non−inverting in operation; therefore, a
high state on the input turns on the specified output current
component.
The switch uses current steering for high speed, and a
termination amplifier consisting of an active load gain stage
with unity gain feedback. The termination amplifier holds
the parasitic capacitance of the ladder at a constant voltage
during switching, and provides a low impedance
termination of equal voltage for all legs of the ladder.
The R−2R ladder divides the reference amplifier current
into binary−related components, which are fed to the
remainder current which is equal to the least significant bit.
This current is shunted to ground, and the maximum output
current is 255/256 of the reference amplifier current, or
1.992 mA for a 2.0 mA reference amplifier current if the
NPN current source pair is perfectly matched.
corresponding to the minimum input level. R15 may be
eliminated and Pin 15 grounded, with only a small sacrifice
in accuracy and temperature drift.
The compensation capacitor value must be increased with
increasing values of R14 to maintain proper phase margin.
For R14 values of 1.0, 2.5, and 5.0 kW, minimum capacitor
values are 15, 37, and 75 pF. The capacitor may be tied to
either VEE or ground, but using VEE increases negative
supply rejection. (Fluctuations in the negative supply have
more effect on accuracy than do any changes in the positive
supply.)
A negative reference voltage may be used if R14 is
grounded and the reference voltage is applied to R15, as
shown in Figure 4. A high input impedance is the main
advantage of this method. The negative reference voltage
must be at least 3.0 V above the VEE supply. Bipolar input
signals may be handled by connecting R14 to a positive
reference voltage equal to the peak positive input level at
Pin 15.
Capacitive bypass to ground is recommended when a DC
reference voltage is used. The 5.0 V logic supply is not
recommended as a reference voltage, but if a well regulated
5.0 V supply which drives logic is to be used as the
reference, R14 should be formed of two series resistors and
the junction of the two resistors bypassed with 0.1 mF to
ground. For reference voltages greater than 5.0 V, a clamp
diode is recommended between Pin 14 and ground.
If Pin 14 is driven by a high impedance such as a transistor
current source, none of the above compensation methods
apply and the amplifier must be heavily compensated,
decreasing the overall bandwidth.
Functional Description
Reference Amplifier Drive and Compensation
The reference amplifier input current must always flow
into Pin 14. regardless of the setup method or reference
supply voltage polarity.
Connections for a positive reference voltage are shown in
Figure 3. The reference voltage source supplies the full
reference current. For bipolar reference signals, as in the
multiplying mode, R15 can be tied to a negative voltage
VCC
A1
A2
A3
A4
A5
A6
A7
A8
VCC
R14 = R15
13
5
6
14
7
15
8
1
9
MC1408 2
10
4
11
16
A1
R14
(+)VREF
A2
A3
R15
A4
A5
RL
A6
IO
A7
12
A8
C
3
R14 = R15
13
5
6
14
7
15
8
1
9
MC1408 2
10
4
11
16
R14
(−)VREF
R15
RL
IO
12
C
3
SEE TEXT FOR VALUES OF C.
VEE
SEE TEXT FOR VALUES OF C.
VEE
Figure 3. Positive VREF
Figure 4. Negative VREF
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5
MC1408−8
Output Voltage Range
current drift. Relative accuracy is the measure of each output
current level as a fraction of the full−scale current after
zero−scale current has been nulled out. The relative
accuracy of the MC1408−8 is essentially constant over the
operating temperature range because of the excellent
temperature tracking of the monolithic resistor ladder. The
reference current may drift with temperature, causing a
change in the absolute accuracy of output current; however,
the MC1408−8 has a very low full−scale current drift over
the operating temperature range.
The MC1408−8 series is guaranteed accurate to within
±1/2 LSB at +25 °C at a full−scale output current of
1.99 mA. The relative accuracy test circuit is shown in
Figure 5. The 12−bit converter is calibrated to a full−scale
output current of 1.99219 mA; then the MC1408−8’s
full−scale current is trimmed to the same value with R14 so
that a zero value appears at the error amplifier output. The
counter is activated and the error band may be displayed on
the oscilloscope, detected by comparators, or stored in a
peak detector.
Two 8−bit D−to−A converters may not be used to
construct a 16−bit accurate D−to−A converter. 16−bit
accuracy implies a total of ±1/2 part in 65,536, or
±0.00076%, which is much more accurate than the ±0.19%
specification of the MC1408−8.
The voltage at Pin 4 must always be at least 4.5 V more
positive than the voltage of the negative supply (Pin 3) when
the reference current is 2.0 mA or less, and at least 8 V more
positive than the negative supply when the reference current
is between 2.0 mA and 4.0 mA. This is necessary to avoid
saturation of the output transistors, which would cause
serious degradation of accuracy.
ON Semiconductor’s MC1408−8 does not need a range
control because the design extends the compliance range
down to 4.5 V (or 8.0 V−see above) above the negative
supply voltage without significant degradation of accuracy.
ON Semiconductor’s MC1408−8 can be used in sockets
designed for other manufacturers’ MC1408 without circuit
modification.
Output Current Range
Any time the full−scale current exceeds 2.0 mA, the
negative supply must be at least 8.0 V more negative than
the output voltage. This is due to the increased internal
voltage drops between the negative supply and the outputs
with higher reference currents.
Accuracy
Absolute accuracy is the measure of each output current
level with respect to its intended value, and is dependent
upon relative accuracy, full−scale accuracy and full−scale
MSB
A1
A2
12-BIT
A3
D-TO-A
A4 CONVERTER
(±0.02%
A5
A6 ERROR MAX)
A7
A8A9A10A11 A12
0 TO +10V OUTPUT
5kW
LSB
50kW
VREF = 2V
100W
8-BIT
COUNTER
0.1mF
950W
R14
VCC
13
MSB14
5
6
7
8
MC1408
9
10
11
12
LSB
15 16 3 2 1
C
1kW
VEE
Figure 5. Relative Accuracy
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6
−
+
NE530
4
ERROR (1V = 1%)
MC1408−8
applies when RL < 500 W and CO < 25 pF. The slowest single
switch is the least significant bit, which typically turns on
and settles in 65 ns. In applications where the D−to−A
converter functions in a positive going ramp mode, the
worst−case condition does not occur and settling times less
than 70 ns may be realized.
Extra care must be taken in board layout since this usually
is the dominant factor in satisfactory test results when
measuring settling time. Short leads, 100 mF supply
bypassing for low frequencies, minimum scope lead length,
good ground planes, and avoidance of ground loops are all
mandatory.
Monotonicity
A monotonic converter is one which always provides an
analog output greater than or equal to the preceding value for
a corresponding increment in the digital input code. The
MC1408−8 is monotonic for all values of reference current
above 0.5 mA. The recommended range for operation is a
DC reference current between 0.5 mA and 4.0 mA.
Settling Time
The worst case switching condition occurs when all bits
are switched on, which corresponds to a low−to−high
transition for all input bits. This time is typically 70 ns for
settling to within 1/2LSB for 8−bit accuracy. This time
VCC
0.1mF
eIN
13
5
6
7
8
9
10
11
12
eIN
14
15
1
MC1408 2
4
16
51W
1.0k
W
15pF
3
0.1mF
1.0kW
+2VDC
R14
2.4V
1.4V
0.4V
tPHL = tPLH = 10ns
1.0V
SETTLING TIME
0.1mF
0
FOR SETTLING TIME
MEASUREMENT
eO (ALL BITS
SWITCHED LOW
TO HIGH)
TRANSIENT 0
RESPONSE
CO ≤ 25pF
−100
mV
RL
USE RL to GND
FOR TURN OFF
MEASUREMENT
RL = 500W
tS = 70ns TYPICAL
TO ±1/2LSB
tPLH
RL = 50W
PIN 4 TO GND
tPHL
VEE
Figure 6. Transient Response and Settling Time
VCC
ICC
13
DIGITAL
INPUTS
A1 5
A2 6
A3 7
A4 8
A5 9
A6 10
A7 11
A8 12
MC1408
(+) II
VI
3
IEE
TYPICAL VALUES R14 = R15 = 1k
VREF = +2.0V
C = 15pF
VI AND II APPLY TO INPUTS A1 THROUGH A8
I14 R14
THE RESISTOR TIED TO PIN 15 IS TO TEMPERATURE
14
VREF(+)
COMPENSATE THE BIAS CURRENT AND MAY NOT BE
I15
NECESSARY FOR ALL APPLICATIONS
15
R15
1
A
A
A
A
A1
A
A
A
2
IO + K
) 2 ) 3 ) 4 ) 5 ) 6 ) 7 ) 8
2
4
8
16
32
64
128
256
4
VO
V
OUTPUT
where K + REF
16
IO
R 14
RL
and AN = “1” IF AN IS AT HIGH LEVEL
NJ
AN = “0” IF AN IS AT LOW LEVEL
VEE
(SEE TEXT FOR VALUES OF C)
Figure 7. Notation Definitions
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7
Nj
MC1408−8
VCC
13
5
14
6
7
15
1
8
9 MC1408 2
10
4
11
16
12
3
1kW
VREF
1kW
15pF
SCOPE
RL = 50W
dI
I dV
+
dt
R L dt
10%
90%
0
2.0mA
SLEWING TIME
VEE
Figure 8. Reference Current Slew Rate Measurement
ORDERING INFORMATION
Device
Temperature Range
Package
MC1408−8D
SOIC−16
MC1408−8DG
SOIC−16
(Pb−Free)
MC1408−8DR2
MC1408−8DR2G
Shipping†
48 Units/Rail
SOIC−16
0°C to +70°C
SOIC−16
(Pb−Free)
MC1408−8N
PDIP−16
MC1408−8NG
PDIP−16
(Pb−Free)
2500 Tape and Reel
25 Units/Rail
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
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8
MC1408−8
PACKAGE DIMENSIONS
PDIP−16
CASE 648−08
ISSUE T
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEADS
WHEN FORMED PARALLEL.
4. DIMENSION B DOES NOT INCLUDE
MOLD FLASH.
5. ROUNDED CORNERS OPTIONAL.
−A−
16
9
1
8
B
F
C
L
DIM
A
B
C
D
F
G
H
J
K
L
M
S
S
SEATING
PLANE
−T−
K
H
G
D
M
J
16 PL
0.25 (0.010)
T A
M
M
INCHES
MIN
MAX
0.740 0.770
0.250 0.270
0.145 0.175
0.015 0.021
0.040
0.70
0.100 BSC
0.050 BSC
0.008 0.015
0.110 0.130
0.295 0.305
0_
10 _
0.020 0.040
MILLIMETERS
MIN
MAX
18.80 19.55
6.35
6.85
3.69
4.44
0.39
0.53
1.02
1.77
2.54 BSC
1.27 BSC
0.21
0.38
2.80
3.30
7.50
7.74
0_
10 _
0.51
1.01
SOIC−16
CASE 751B−05
ISSUE J
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
−A−
16
9
1
8
−B−
P
8 PL
0.25 (0.010)
M
B
S
G
R
K
F
X 45 _
C
−T−
SEATING
PLANE
J
M
D
16 PL
0.25 (0.010)
M
T B
S
A
DIM
A
B
C
D
F
G
J
K
M
P
R
MILLIMETERS
MIN
MAX
9.80
10.00
3.80
4.00
1.35
1.75
0.35
0.49
0.40
1.25
1.27 BSC
0.19
0.25
0.10
0.25
0_
7_
5.80
6.20
0.25
0.50
INCHES
MIN
MAX
0.386
0.393
0.150
0.157
0.054
0.068
0.014
0.019
0.016
0.049
0.050 BSC
0.008
0.009
0.004
0.009
0_
7_
0.229
0.244
0.010
0.019
S
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
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Email: [email protected]
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ON Semiconductor Website: www.onsemi.com
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For additional information, please contact your local
Sales Representative
MC1408−8/D
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