DAC08CSZ Analog Devices Inc, DAC08CSZ Datasheet - Page 11

• Manufacturer Part Number: DAC08CSZ
• Description: IC DAC 8BIT MULTIPLY HS 16-SOIC
• Manufacturer: Analog Devices Inc

Specifications of DAC08CSZ

• Data Interface: Parallel
• Settling Time: 85ns
• Number Of Bits: 8
• Number Of Converters: 1
• Voltage Supply Source: Dual ±
• Power Dissipation (max): 174mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Resolution (bits): 8bit
• Sampling Rate: 11.8MSPS
• Input Channel Type: Parallel
• Supply Current: -6.5mA
• Digital Ic Case Style: SOIC
• No. Of Pins: 16
• Number Of Channels: 1
• Resolution: 8b
• Interface Type: Parallel
• Single Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (typ): ±15V
• Architecture: Current Steering
• Power Supply Requirement: Dual
• Output Type: Current
• Single Supply Voltage (min): Not RequiredV
• Single Supply Voltage (max): Not RequiredV
• Dual Supply Voltage (min): ±4.5V
• Dual Supply Voltage (max): ±18V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 16
• Package Type: SOIC N
• Supply Voltage Range - Analog: ± 4.5V To ± 18V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

range, negative logic input range and negative logic threshold
range; consult the various figures for guidance. For example,
operation at –4.5 V with I
because negative output compliance would be reduced to near
zero. Operation from lower supplies is possible; however, at
least 8 V total must be applied to ensure turn-on of the internal
bias network.
Symmetrical supplies are not required, as the DAC08 is quite
insensitive to variations in supply voltage. Battery operation is
feasible as no ground connection is required: however, an artificial
ground may be used to ensure logic swings, etc., remain
between acceptable limits.
Power consumption may be calculated as follows:
A useful feature of the DAC08 design is that supply current is
constant and independent of input logic states; this is useful in
cryptographic applications and further serves to reduce the size
of the power supply bypass capacitors.
TEMPERATURE PERFORMANCE
The nonlinearity and monotonicity specifications of the DAC08
are guaranteed to apply over the entire rated operating temperature
range. Full-scale output current drift is low, typically ±10 ppm/°C,
with zero-scale output current and drift essentially negligible
compared to 1/2 LSB.
The temperature coefficient of the reference resistor R14 should
match and track that of the output resistor for minimum overall
full-scale drift. Settling times of the DAC08 decrease approxi-
mately 10% at –55°C; at +125°C an increase of about 15%
is typical.
The reference amplifier must be compensated by using a capacitor
from pin 16 to V–. For fixed reference operation, a 0.01 µF
capacitor is recommended. For variable reference applications,
see “Reference Amplifier Compensation for Multiplying Applica-
tions” section.
MULTIPLYING OPERATION
The DAC08 provides excellent multiplying performance with an
extremely linear relationship between I
of 4 µA to 4 mA. Monotonic operation is maintained over a
typical range of I
REF
P
D
from 100 µA to 4.0 mA.
= (I+) (V+) + (I–) (V–)
+V
0.7V
V
REF
REF
CL
= 2 mA is not recommended
R
R15
REF
0.1 F
14
15
0.1 F
FS
5
+15V
and I
6 7 8 9 10 11 12
13
DAC08
FOR TURN-ON, V
FOR TURN-OFF, V
V
–15V
REF
IN
3
over a range
16
CAPACITANCE
0.01 F
0.1 F
MINIMUM
4
2
L
L
= 2.7V
= 0.7V
I
OUT
Q1
V
L
1k
SETTLING TIME
The DAC08 is capable of extremely fast settling times, typically
85 ns at I
board layout must be employed to obtain full performance
potential during testing and application. The logic switch design
enables propagation delays of only 35 ns for each of the 8 bits.
Settling time to within 1/2 LSB of the LSB is therefore 35 ns,
with each progressively larger bit taking successively longer. The
MSB settles in 85 ns, thus determining the overall settling time
of 85 ns. Settling to 6-bit accuracy requires about 65 ns to 70 ns.
The output capacitance of the DAC08 including the package is
approximately 15 pF, therefore the output RC time constant
dominates settling time if R
Settling time and propagation delay are relatively insensitive to
logic input amplitude and rise and fall times, due to the high
gain of the logic switches. Settling time also remains essentially
constant for I
values lies in the ability to attain a given output level with lower
load resistors, thus reducing the output RC time constant.
Measurement of settling time requires the ability to accurately
resolve ± 4 µA, therefore a 1 kΩ load is needed to provide
adequate drive for most oscilloscopes. The settling time fix-
ture shown in schematic labelled “Settling Time Measurement”
uses a cascade design to permit driving a 1 kΩ load with less
than 5 pF of parasitic capacitance at the measurement node. At
I
output is difficult to prevent while maintaining adequate sensi-
tivity. However, the major carry from 01111111 to 10000000
provides an accurate indicator of settling time. This code change
does not require the normal 6.2 time constants to settle to
within ± 0.2% of the final value, and thus settling times may be
observed at lower values of I
DAC08 switching transients or “glitches” are very low and may
be further reduced by small capacitive loads at the output at a
minor sacrifice in settling time.
Fastest operation can be obtained by using short leads, minimizing
output capacitance and load resistor values, and by adequate
bypassing at the supply, reference, and V
do not require large electrolytic bypass capacitors as the supply
current drain is independent of input logic states; 0.1 µF capacitors
at the supply pins provide full transient protection.
REF
100k
values of less than 1.0 mA, excessive RC damping of the
1k
1 F
REF
2k
REF
50 F
= 2.0 mA. Judicious circuit design and careful
1 F
values. The principal advantage of higher I
–15V
+5V
Q2
15k
V
PROBE
OUT
L
REF
1X
> 500 Ω.
.
+0.4V
–0.4V
0.1 F
0V
0V
LC
terminals. Supplies
DAC08
REF