PHILIPS DAC08C

Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DESCRIPTION
DAC08 Series
PIN CONFIGURATIONS
The DAC08 series of 8-bit monolithic multiplying Digital-to-Analog
Converters provide very high-speed performance coupled with low
cost and outstanding applications flexibility.
F, N Packages
VLC 1
Advanced circuit design achieves 70ns settling times with very low
glitch and at low power consumption. Monotonic multiplying
performance is attained over a wide 20-to-1 reference current range.
Matching to within 1 LSB between reference and full-scale currents
eliminates the need for full-scale trimming in most applications.
Direct interface to all popular logic families with full noise immunity is
provided by the high swing, adjustable threshold logic inputs.
16 COMP
2
15 VREF–
V– 3
14 V
REF+
IO 4
13 V+
IO
B1 (MSB) 5
Dual complementary outputs are provided, increasing versatility and
enabling differential operation to effectively double the peak-to-peak
output swing. True high voltage compliance outputs allow direct
output voltage conversion and eliminate output op amps in many
applications.
12 B8 (LSB)
B2 6
11 B7
B3 7
10 B6
B4 8
9
B5
TOP VIEW
D1 Package
All DAC08 series models guarantee full 8-bit monotonicity and
linearities as tight as 0.1% over the entire operating temperature
range. Device performance is essentially unchanged over the ±4.5V
to ±18V power supply range, with 37mW power consumption
attainable at ±5V supplies.
V+ 1
15 B7
3
14 B6
COMPEN 4
13 B5
VLC 5
12 B4
VREF–
The compact size and low power consumption make the DAC08
attractive for portable and military aerospace applications.
6
11 B3
V– 7
10 B2
IO 8
9
IO
FEATURES
• Fast settling output current—70ns
• Full-scale current prematched to ±1 LSB
• Direct interface to TTL, CMOS, ECL, HTL, PMOS
• Relative accuracy to 0.1% maximum over temperature range
• High output compliance -10V to +18V
• True and complemented outputs
• Wide range multiplying capability
• Low FS current drift — ±10ppm/°C
• Wide power supply range—±4.5V to ±18V
• Low power consumption—37mW at ±5V
16 B8 (LSB)
VREF+ 2
B1 (MSB)
TOP VIEW
NOTE:
1. SO and non-standard pinouts.
• Waveform generators
• Audio encoders and attenuators
• Analog meter drivers
• Programmable power supplies
• CRT display drivers
• High-speed modems
• Other applications where low cost, high speed and complete input/output versatility are required
• Programmable gain and attenuation
• Analog-Digital multiplication
APPLICATIONS
• 8-bit, 1µs A-to-D converters
• Servo-motor and pen drivers
August 31, 1994
716
853-0045 13721
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
ORDERING INFORMATION
DESCRIPTION
TEMPERATURE RANGE
ORDER CODE
DWG #
16-Pin Hermetic Ceramic Dual In-Line Package (Cerdip)
-55°C to +125°C
DAC08F
0582B
16-Pin Hermetic Ceramic Dual In-Line Package (Cerdip)
-55°C to +125°C
DAC08AF
0582B
16-Pin Plastic Dual In-Line Package (DIP)
0 to +70°C
DAC08CN
0406C
16-Pin Hermetic Ceramic Dual In-Line Package (Cerdip)
0 to +70°C
DAC08CF
0582B
16-Pin Plastic Dual In-Line Package (DIP)
0 to +70°C
DAC08EN
0406C
16-Pin Hermetic Ceramic Dual In-Line Package (Cerdip)
0 to +70°C
DAC08EF
0582B
16-Pin Plastic Small Outline (SO) Package
0 to +70°C
DAC08ED
0005D
16-Pin Plastic Dual In-Line Package (DIP)
0 to +70°C
DAC08HN
0406C
BLOCK DIAGRAM
V+
MSB
B1
VLC
13
1
5
B2
6
B3
7
B4
8
B5
9
B6
10
LSB
B8
B7
11
12
4
BIAS
NETWORK
CURRENT
SWITCHES
14
VREF(+)
VREF(–)
2
IOUT
IOUT
+
–
15
REFERENCE
AMPLIFIER
16
COMP.
3
V–
ABSOLUTE MAXIMUM RATINGS
SYMBOL
PARAMETER
RATING
UNIT
36
V
V+ to V-
Power supply voltage
V5-V12
Digital input voltage
VLC
Logic threshold control
V- to V+
V0
Applied output voltage
V- to +18
V
I14
Reference current
5.0
mA
V14, V15
Reference amplifier inputs
PD
Maximum power dissipation TA=25°C
(still-air)1
V- to V- plus 36V
VEE to VCC
F package
1190
mW
N package
1450
mW
D package
1090
mW
300
°C
-55 to +125
°C
0 to +70
°C
-65 to +150
°C
TSOLD
Lead soldering temperature (10sec max)
TA
Operating temperature range
DAC08, DAC08A
DAC08C, E, H
TSTG
Storage temperature range
NOTES:
1. Derate above 25°C, at the following rates:
F package at 9.5mW/°C
N package at 11.6mW/°C
D package at 8.7mW/°C
August 31, 1994
717
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
DC ELECTRICAL CHARACTERISTICS
Pin 3 must be at least 3V more negative than the potential to which R15 is returned. VCC=±15V, IREF=2.0mA. Output characteristics refer to both
IOUT and IOUT unless otherwise noted. DAC08C, E, H: TA=0°C to 70°C DAC08/08A: TA=-55°C to 125°C
SYMBOL
PARAMETER
DAC08E
DAC08
DAC08C
TEST CONDITIONS
UNIT
Min
Typ
Max
Min
Typ
Max
Resolution
8
8
8
8
8
8
Bits
Monotonicity
8
8
8
8
8
8
Bits
±0.39
±0.19
%FS
±0.78
±0.39
%FS
Relative accuracy
Over temperature range
Differential non-linearity
±10
TCIFS
Full-scale tempco
VOC
Output voltage compliance
Full-scale current change< 1/2LSB
-10
IFS4
Full-scale current
VREF=10.000V, R14, R15=5.000kΩ
1.94
IFSS
Full-scale symmetry
IZS
Zero-scale current
IFSR
Full-scale output current
range
IFS4-IFS2
R14, R15=5.000kΩ
VREF=+15.0V, V-=-10V
VREF=+25.0V, V-=-12V
2.1
4.2
2.0
VIL
VIH
Logic input levels
Low
High
VLC=0V
IIL
IIH
Logic input current
Low
High
VLC=0V
VIN=-10V to +0.8V
VIN=2.0V to 18V
VIS
Logic input swing
V-=-15V
-10
VTHR
Logic threshold range
VS=±15V
-10
I15
Reference bias current
dl/dt
Reference input slew rate
Power supply sensitivity
±10
+18
-10
1.99
2.04
1.94
±2.0
0.2
V
1.99
2.04
mA
±16
±1.0
±8.0
µA
4.0
0.2
2.0
µA
2.1
4.2
mA
0.8
0.8
V
-10
10
µA
+18
V
2.0
-2.0
0.002
-1.0
4.0
ppm/°C
+18
-10
10
-2.0
0.002
+18
-10
+13.5
-10
-3.0
8.0
-1.0
4.0
+13.5
V
-3.0
µA
8.0
mA/µs
IREF=1mA
PSSIFS+
Positive
V+=4.5 to 5.5V, V-=-15V;
0.0003
0.01
0.0003
0.01
PSIFS-
Negative
V-=-4.5 to -5.5V, V+=+15V;
0.002
0.01
0.002
0.01
VS=±5V, IREF=1.0mA
3.1
-4.3
3.8
-5.8
3.1
-4.3
3.8
-5.8
V+=13.5 to 16.5V, V-=-15V
%FS/%VS
V-=-13.5 to -16.5, V+=+15V
I+
I-
Power supply current
Positive
Negative
I+
I-
Positive
Negative
VS=+5V, -15V, IREF=2.0mA
3.1
-7.1
3.8
-7.8
3.1
-7.1
3.8
-7.8
I+
I-
Positive
Negative
VS=±15V, IREF=2.0mA
3.2
-7.2
3.8
-7.8
3.2
-7.2
3.8
-7.8
PD
Power dissipation
August 31, 1994
±5V, IREF=1.0mA
37
48
37
48
+5V, -15V, IREF=2.0mA
122
136
122
136
±15V, IREF=2.0mA
156
174
156
174
718
mA
mW
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
DC ELECTRICAL CHARACTERISTICS (Continued)
Pin 3 must be at least 3V more negative than the potential to which R15 is returned. VCC = +15V, IREF = 2.0mA, Output characteristics refer to
both IOUT and IOUT, unless otherwise noted. DAC08C, E, H: TA = 0°C to 70°C. DAC08/08A: TA = -55°C to 125°C.
SYMBOL
PARAMETER
DAC08H
DAC08A
TEST CONDITIONS
Typ
Max
Resolution
8
8
8
Monotonicity
8
8
8
Bits
±0.1
%FS
Relative accuracy
Over temperature range
Full-scale tempco
VOC
Output voltage compliance
Full-scale current change 1/2LSB
-10
IFS4
Full-scale current
VREF=10.000V, R14, R15=5.000kΩ
1.984
IFSS
Full-scale symmetry
IZS
Zero-scale current
Full-scale output current range
IFS4-IFS2
R14, R15=5.000kΩ
VREF=+15.0V, V-=-10V
VREF=+25.0V, V-=-12V
2.1
4.2
2.0
VIL
VIH
Logic input levels
Low
High
VLC=0V
IIL
IIH
Logic input current
Low
High
VLC=0V
VIN=-10V to +0.8V
VIN=2.0V to 18V
VIS
Logic input swing
V-=-15V
VTHR
Logic threshold range
VS=±15V
I15
Reference bias current
dl/dt
Reference input slew rate
Power supply sensitivity
PSSIFS+
Positive
±0.19
%FS
±50
ppm/°C
+18
V
1.992
2.000
mA
±1.0
±4.0
µA
0.2
1.0
µA
mA
0.8
V
-10
10
µA
-10
+18
V
-10
+13.5
V
-3.0
µA
-2.0
0.002
-1.0
4.0
8.0
mA/µs
IREF=1mA
V+=4.5 to 5.5V, V-=-15V;
0.0003
0.01
0.002
0.01
3.1
-4.3
3.8
-5.8
V+=13.5 to 16.5V, V-=-15V
PSIFS-
Negative
Bits
±10
Differential non-linearity
TCIFS
IFSR
UNIT
Min
V-=-4.5 to -5.5V, V+=+15V;
%FS/%VS
V-=-13.5 to -16.5, V+=+15V
I+
I-
Power supply current
Positive
Negative
VS=±5V, IREF=1.0mA
I+
I-
Positive
Negative
VS=+5V, -15V, IREF=2.0mA
3.1
-7.1
3.8
-7.8
I+
I-
Positive
Negative
VS=±15V, IREF=2.0mA
3.2
-7.2
3.8
-7.8
PD
Power dissipation
August 31, 1994
±5V, IREF=1.0mA
37
48
+5V, -15V, IREF=2.0mA
122
136
±15V, IREF=2.0mA
156
174
719
mA
mW
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
AC ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
Min
tS
To ± 1/2LSB, all bits
switched on or off,
TA=25°C
Settling time
DAC08E
DAC08
DAC08C
TEST CONDITIONS
Typ
Max
70
35
Min
DAC08H
DAC08A
Typ
Max
135
70
60
35
Min
UNIT
Typ
Max
135
70
135
60
35
60
ns
Propagation delay
tPLH
Low-to-High
TA=25°C, each bit.
tPHL
High-to-Low
All bits switched
ns
TEST CIRCUITS
VREF
V–
V+
3
13
RREF
16
14
DAC-08
15
5-12
4
1
Rf
2
R15
–
NE5534
CONTROL
LOGIC
ERROR
OUTPUT
+
REFERENCE DAC
ACCURACY > 0.006%
Figure 1. Relative Accuracy Test Circuit
0.1µF VCC
2.4V
eIN
13
+2.0VDC
5
6
7
8
9
10
11
12
eIN
DAC-08
51
0.1µF
14
15
1
2
4
16
tPHL = tPLH = 10ns
1.0k
1.0k
15pF
1.0V
RL
SETTLING TIME
0.1µF
FOR SETTLING TIME
MEASUREMENT
eO (ALL BITS
SWITCHED LOW
TO HIGH)
CO ≤ 25pF
0
tS = 70ns TYPICAL
TO ±1/2 LSB
TRANSIENT 0
RESPONSE
-100mV
3
RL = 50Ω
PIN 4 TO GND
tPLH
Figure 2. Transient Response and Settling Time
720
USE RL to GND
FOR TURN OFF
MEASUREMENT
RL = 500Ω
VEE
August 31, 1994
1.4V
0.4V
tPHL
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
TEST CIRCUITS (Continued)
VCC
2V
RIN
13
1k
5
REQ = 200Ω
6
14
7
15
8
0
VIN
RP
1
DAC-08
9
2
10
4
11
16
OPEN
12
10%
RL
0.1µF
3
dI
I dV
R L dt
dt
SCOPE
2.0mA
SLEWING TIME
VEE
Figure 3. Reference Current Slew Rate Measurement
VCC
ICC
13
I14
5
A1
A2
A3
A4
A5
DIGITAL
INPUTS
A6
A7
VREF (+)
6
7
15
8
1
DAC-08
9
I15
R15
2
10
VO
OUTPUT
4
11
12
16
A8
(+)
R14
14
II
VI
IO
C
3
RL
IEE
NOTES:
(See text for values of C.)
VEE
Typical values of R14 = R15 = 1k
VREF = +2.0V
C = 15pF
VI and II apply to inputs A1 through A8
The resistor tied to Pin 15 is to temperature compensate the bias current and may not be necessary for all applications.
I
O
K
A1
2
where K A2
4
A3
8
A4
16
A5
32
A6
64
A8
A7
128
256
V REF
R 14
and AN = ‘1’ if AN is at High Level
AN = ‘0’ if AN is at Low Level
Figure 4. Notation Definitions
August 31, 1994
721
0
90%
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
TYPICAL PERFORMANCE CHARACTERISTICS
Output Current vs Output Voltage
(Output Voltage Compliance)
True and Complementary Output
Operation
Fast Pulsed Reference Operation
ALL BITS ON
OUTPUT CURRENT (mA)
3.2
TA = Tmin TO Tmax
2.8
2.5V
0mA
VIN
2.4
V– = –15V
IREF = 2mA
V– = –5V
2.0
0.5V
1.0mA
–0.5mA
1.6
IOUT
IREF = 1mA
1.2
–2.5mA
IOUT
2.0mA
0.8
IREF = 0.2mA
0.4
(00000000)
0
–14 –10
–6 –2 0 2
6
10
OUTPUT VOLTAGE (V)
14
REQ = 200Ω, RL = 100Ω, CC = 0
Full-Scale Current vs
Reference Current
LSB Switching
2.4V
I FS – OUTPUT CURRENT (mA)
ALL BITS SWITCHED ON
BIT 8 2.4V
LOGIC
INPUT
0.4V
0V
0.4V
OUTPUT – 1/2LSB
0
SETTLING +1/2LSB
8µA
IOUT
0
50ns/DIVISIOM
50ns/DIVISIOM
IFS=2mA, RL=1kΩ 1/2LSB=4µA
5.0
TA = Tmin TO Tmax
ALL BITS “HIGH”
4.0
3.0
LIMIT FOR
V–=–5V
2.0
1.0
0
LSB Propagation Delay vs IFS
Reference Input Frequency Response
6
RELATIVE OUTPUT (dB)
4
400
300
200
1LSB=7.8µA
100
10
5.0
2.0
1.0
0.5
0.2
0.1
.05
.02
.05
.01
1LSB=78nA
2
0
–2
–4
–6
–8
1
–10
RL ≤ 500Ω
ALL BITS “ON”
–12
VR15 = 0V
–14
0.1
2
R14=R15=1kΩ
0.2
3
0.5
1.0
2.0
FREQUENCY (MHz)
5.0
10
IFS — OUTPUT FULL SCALE CURRENT (mA)
NOTES:
Curve 1:
Curve 1:
Curve 1:
August 31, 1994
LIMIT FOR
V–=–15V
0
500
0
(11111111)
200ns/division
18
Full-Scale Settling Time
PROPAGATION DELAY (ns)
IOUT
CC = 15pF, VIN = 2.0VP-P centered at +1.0V
CC = 15pF, VIN = 5m0VP-P centered at +200mV
CC = 15pF, VIN = 100m0VP-P centered at 0V
and applied through 50Ω connected to Pin 14.
+2.0V applied to R14.
722
1.0
2.0
3.0
4.0
5.0
IREF — REFERENCE CURRENT (mA)
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
2.4
V– = –5V
V+ = +5V
IREF = 2mA
1.6
1.2
0.8
IREF = 1mA
IREF = 0.2mA
0.4
0
–14 –10 –6
–2 0 2
6
10
6.0
4.0
2.0
0
–12
14 18
–8 –4
0
4
8 12
LOGIC INPUT VOLTAGE (V)
V15 — REFERENCE COMMON MODE VOLTAGE (V)
POSITIVE COMMON-MODE RANGE IS ALWAYS (V+) –1.5V.
20
1.4
16
1.2
12
Shaded area indicates
permissible output voltage
8
range for V– = -15V, IREF ≤ 2.0mA
4
For other V– or IREF
See “Output Current vs Output
Voltage” curve on previous page
0
–4
IREF = 2.0mA
B2
0.4
V– = –15V
V– = –5V
–8
0
–12
–12
–50
0
50
100
150
TEMPERATURE (°C)
B1
0.8
0.2
B3
B4
B5
–8
–4
0
4
8
12
LOGIC INPUT VOLTAGE (V)
0
50
100
TEMPERATURE (°C)
150
Power Supply Current vs V+
1.0
0.6
–50
16
Bit Transfer Characteristics
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
Output Voltage Compliance
vs Temperature
2.0
1.8
1.6
1.4
1.2
1.o
0.8
0.6
0.4
0.2
0
POWER SUPPLY CURRENT (mA)
V– = –15V
2.0
8.0
(V)
TA = TMIN to TMAX
LOGIC INPUT CURRENT ( µ A)
OUTPUT CURRENT (mA)
3.2
2.8
VTH – VLC vs Temperature
Logic Input Current vs Input Voltage
VTHLC– V
Reference AMP Common-Mode Range
All Bits On
8
7
ALL BITS HIGH OR LOW
I–
6
5
4
3
I+
2
1
0
–50
0
50
100
150
V+ – POSITIVE POWER SUPPLY (VDC)
16
NOTES:
B1 through B8 have identical transfer characteristics.
Bits are fully switched, with less than 1/2LSB error, at
less than ±100mV from actual threshold. These
switching points are guaranteed to lie between 0.8 and
2.0V over the operating temperature range
(VLC = 0.0V).
Maximum Reference Input Frequency
vs Compensation Capacitor Value
Power Supply Current vs V–
Power Supply Current vs Temperature
BITS MAY BE HIGH OR LOW
I– WITH IREF = 2mA
7
6
I– WITH IREF = 1mA
5
4
I– WITH IREF = 0.2mA
3
2
I+
1
0
0
–4.0
–8.0
–12
–16
–20
V– — NEGATIVE POWER SUPPLY (VDC)
8
BITS MAY BE HIGH OR LOW
V– = +15V
I–
7
6
F
(kHz)
MAX
8
POWER SUPPLY CURRENT (mA)
POWER SUPPLY CURRENT (mA)
10,000
IREF = 2.0mA
5
4
3
V+ = +15V
I+
1,000
100
2
1
0
–50
0
50
100
TEMPERATURE (°C)
150
10
1
100
10
CC (pF)
August 31, 1994
723
1000
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
is 2mA or less, and at least 8V more positive than the negative
supply when the reference current is between 2mA and 4mA. This is
necessary to avoid saturation of the output transistors, which would
cause serious accuracy degradation.
TYPICAL APPLICATION
+VREF
OPTIONAL RESISTOR
FOR OFFSET
INPUTS
RIN
0V
RP
Output Current Range
RREF
14
REQ
=200Ω 15 16
Any time the full-scale current exceeds 2mA, the negative supply
must be at least 8V 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.
4
2
NO CAP
Accuracy
NOTES:
REQ = RIN || RP
Typical Values
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 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 DAC08 series is essentially constant
over the operating temperature range due to 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 DAC08 series has a very
low full-scale current drift over the operating temperature range.
RIN = 5kΩ
+VIN = 10V
Pulsed Referenced Operation
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.
The DAC08 series is guaranteed accurate to within ± LSB at +25°C
at a full-scale output current of 1.992mA. The relative accuracy test
circuit is shown in Figure 1. The 12-bit converter is calibrated to a
full-scale output current of 1.99219mA, then the DAC08 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.
Connections for a positive reference voltage are shown in Figure 1.
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 corresponding to the minimum input level.
R15 may be eliminated with only a small sacrifice in accuracy and
temperature drift.
The compensation capacitor value must be increased as R14 value
is increased. This is in order to maintain proper phase margin. For
R14 values of 1.0, 2.5, and 5.0kΩ, minimum capacitor values are 15,
37, and 75pF, respectively. 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.)
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 ± part in
65,536, or ±0.00076%, which is much more accurate than the
±0.19% specification of the DAC08 series.
Monotonicity
A monotonic converter is one which always provides analog output
greater than or equal to the preceding value for a corresponding
increment in the digital input code. The DAC08 series is monotonic
for all values of reference current above 0.5mA. The recommended
range for operation is a DC reference current between 0.5mA and
4.0mA.
A negative reference voltage may be used if R14 is grounded and
the reference voltage is applied to R15 as shown. A high input
impedance is the main advantage of this method. The negative
reference voltage must be at least 3.0V 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.
Settling Time
When using a DC reference voltage, capacitive bypass to ground is
recommended. The 5.0V logic supply is not recommended as a
reference voltage, but if a well regulated 5.0V supply which drives
logic is to be used as the reference, R14 should be formed of two
series resistors with the junction of the two resistors bypassed with
0.1µF to ground. For reference voltages greater than 5.0V, a clamp
diode is recommended between Pin 14 and ground.
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 70ns for settling to within LSB for
8-bit accuracy. This time applies when RL<500Ω and CO<25pF. The
slowest single switch is the least significant bit, which typically turns
on and settles in 65ns. In applications where the DAC functions in a
positive-going ramp mode, the worst-case condition does not occur
and settling times less than 70ns may be realized.
If Pin 14 is driven by a high impedance such as a transistor current
source, none of the above compensation methods applies and the
amplifier must be heavily compensated, decreasing the overall
bandwidth.
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, 100µF supply bypassing for low frequencies,
minimum scope lead length, and avoidance of ground loops are all
mandatory.
Output Voltage Range
The voltage at Pin 4 must always be at least 4.5V more positive than
the voltage of the negative supply (Pin 3) when the reference current
August 31, 1994
DAC08 Series
724
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
SETTLING TIME AND PROPAGATION DELAY
VS + = +15V
VIN
C3
VADJ
Q1
D3
R1 = 1000Ω
5
R14 = 5kΩ
VOUT
6 7 8 9 10 11 12
14
VREF = 10V
R2 = 1000Ω
4
VOUT
DUT
IREF = 2mA
2
15
16
3
C1
R15 = 5kΩ
D1
1
D2
50Ω
C5
C2
R3 = 500Ω
C4
VS – = –15V
NOTES:
D1, D2 = IN6263 or equivalent
D3 = IN914 or equivalent
C1 = 0.01µF
C2, C3 = 0.1µF
Q1 = 2N3904
C4, C5 = 15pF and includes all probe and fixturing capacitance.
BASIC DAC08 CONFIGURATION
MSB 2
3 4 5 6 7
LSB
+VREF
RREF
IREF
5
(LOW T.C.)
6 7 8 9 10 11 12
14
4
IO
2
IO
DAC-08
15
3
16
V–
13
1
V+
CCOMP
0.1µF
0.1µF
NOTES:
V REF
255
I
x
; I I
I
for all logic states
FS
O
O
FS
256
R REF
August 31, 1994
725
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
RECOMMENDED FULL-SCALE AND ZERO-SCALE ADJUST
VREF
R1
R2
14
4
DAC-08
2
15
R3
R4 = 1MΩ
V–
V+
RS = 20kΩ
NOTES:
R1 = low T.C.
R3 = R1 + R2
R2 ≈ 0.1 R1 to minimize pot. contribution to full-scale drift
UNIPOLAR VOLTAGE OUTPUT FOR LOW IMPEDANCE OUTPUT
5kΩ (LOW T.C.)
IR = 2mA
–
NE531
OR
EQUIV
+
4
14
15
DAC-08
2
5kΩ
August 31, 1994
726
VOUT =
0 TO +10V
Philips Semiconductors Linear Products
Product specification
8-Bit high-speed multiplying D/A converter
DAC08 Series
UNIPOLAR VOLTAGE OUTPUT FOR HIGH IMPEDANCE OUTPUT
V = 10V
5kΩ
5kΩ
VOUT
4
IR = 2mA
DAC-08
14
2
VOUT
a. Positive Output
VOUT
4
IR = 2mA
DAC-08
14
2
VOUT
a. Negative Output
BASIC BIPOLAR OUTPUT OPERATION (OFFSET BINARY)
V = 10V
10kΩ
10kΩ
4
IR = 2mA
DAC-08
14
VOUT
2
VOUT
August 31, 1994
B1
B2
B3
B4
B5
B6
B7
B8
VOUT
VOUT
Positive full-scale
1
1
1
1
1
1
1
1
–9.920V
+10.000
Positive FS – 1LSB
1
1
1
1
1
1
1
0
–9.840V
+9.920
+ Zero-scale + 1LSB
Zero-scale
1
1
0
0
0
0
0
0
0
0
0
0
0
0
1
0
–0.080V
0.000
+0.160
+0.080
Zero-scale – 1LSB
0
1
1
1
1
1
1
1
0.080
0.000
Negative full scale – 1LSB
0
0
0
0
0
0
0
1
+9.920
–9.840
Negative full scale
0
0
0
0
0
0
0
0
+10.000
–9.920
727