Analog Devices DAC16GS, DAC16GBS, DAC16FS Datasheet

REV. B
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
a
16-Bit High Speed
Current-Output DAC
FUNCTIONAL BLOCK DIAGRAM
BUFFER
DAC
C
COMP
I
OUT
DB0 (LSB)
DB15 (MSB)
DAC16
I
REF
REF GND
V
CC
AGND
V
EE
DGND
GENERAL DESCRIPTION
The DAC16 is a 16-bit high speed current-output digital-to­analog converter with a settling time of 500 ns. A unique com­bination of low distortion, high signal-to-noise ratio, and high speed make the DAC16 ideally suited to performing waveform synthesis and modulation in communications, instrumentation, and ATE systems. Input reference current is buffered, with full­scale output current of 5 mA. The 16-bit parallel digital input bus is TTL/CMOS compatible. Operating from +5 V and –15 V supplies, the DAC16 consumes 190 mW (typ) and is available in a 24-lead epoxy DIP, epoxy surface-mount small outline (SOL), and in die form.
FEATURES 1 LSB Differential Linearity (max) Guaranteed Monotonic Over Temperature Range 2 LSB Integral Linearity (max) 500 ns Settling Time 5 mA Full-Scale Output TTL/CMOS Compatible Low Power: 190 mW (typ) Available in Die Form
APPLICATIONS Communications ATE Data Acquisition Systems High Resolution Displays
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 1999
SETTLING TIME – ns
0.1
0.01
0.001 0 100
PERCENT OF FULL-SCALE – %
200 300 400 500 600 700 800
V
LOGIC
= 0V
TURNING ON
V
LOGIC
= +5V
TURNING OFF
I
FS
= 4mA
T
A
= 258C
Figure 1. DAC16 Settling Time Accuracy vs. Percent of Full Scale
DAC16–SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
Parameter Conditions Min Typ Max Units
Integral Linearity “G” INL T
A
= +25°C–2±1.2 +2 LSB
Integral Linearity “G” INL –4 ±1.6 +4 LSB
Differential Linearity “G” DNL T
A
= +25°C–1±0.5 +1 LSB
Differential Linearity “G” DNL –1 ±0.7 +1.5 LSB
Integral Linearity “F” INL T
A
= +25°C–4±1.4 +4 LSB
Integral Linearity “F” INL –6 ±2 +6 LSB
Differential Linearity “F” DNL T
A
= +25°C–1±0.5 +1.5 LSB
Differential Linearity “F” DNL –1.5 ±0.6 +2 LSB
Zero Scale Error ZSE 1 LSB Zero Scale Drift TC
ZSE
0.025 ppm/°C
Gain Error GE ±0.225 % FS
Gain Drift TC
GE
5 ppm/°C
REFERENCE
2
Reference Input Current I
REF
Note 2 350 625 µA
OUTPUT CHARACTERISTICS
Output Current I
OUT
Note 2 2.8 5.0 mA
Output Capacitance C
OUT
10 pF
Settling Time t
S
0.003% of Full Scale 500 ns
LOGIC CHARACTERISTICS
Logic Input High Voltage V
INH
T
A
= +25°C 2.4 V
Logic Input Low Voltage V
INL
T
A
= +25°C 0.8 V
Logic Input Current I
INH
V
IN
= 5.0 V, DB0–DB10 7.5 µA
Logic Input Current I
INH
V
IN
= 5.0 V, DB11–DB15 100 µA
Logic Input Current I
INL
V
IN
= 0 V, DB0–DB15 1 µA
Input Capacitance C
IN
8pF
SUPPLY CHARACTERISTICS
Power Supply Sensitivity PSS V
CC
= 4.5 V to 5.5 V, VEE = –13 V to –17 V 20 ppm/V
Positive Supply Current I
CC
All Bits HIGH 15 22 mA
Positive Supply Current I
CC
All Bits LOW 6 7.5 mA
Negative Supply Current I
EE
7.5 10 mA
Power Dissipation P
DISS
188 260 mW
NOTES
1
All supplies can be varied ±5% and operation is guaranteed. Device is tested with nominal supplies.
2
Operation is guaranteed over this reference range, but linearity is neither tested not guaranteed (see Figures 7 and 8).
Specifications subject to change without notice.
WAFER TEST LIMITS
DAC16G
Parameter Symbol Conditions Limit Units
Integral Nonlinearity INL ±3 LSB max Differential Nonlinearity DNL ±1 LSB max Zero Scale Error ZSE ±1 LSB max Gain Error GE ±12 % FS max
Logic Input High Voltage V
INH
2.4 V min
Logic Input Low Voltage V
INL
0.8 V max
Logic Input Current I
IN
75 µA max
Positive Supply Current I
CC
20 mA max
Negative Supply Current I
EE
10 mA max
Power Dissipation P
DISS
250 mW max
NOTE Electrical tests are performed at wafer probe to the limits shown. Due to variations in assembly methods and normal yield loss, yield after packaging is not guaranteed for standard product dice. Consult factory to negotiate specifications based on dice lot qualification through sample lot assembly and testing.
REV. B
–2–
(@ VCC = +5.0 V, VEE = –15.0 V, I
REF
= 0.5 mA, C
COMP
= 47 F, TA = Full Operating Tem-
perature Range unless otherwise noted. See Note 1 for supply variations.)
(@ VCC = +5.0 V, VEE = –15.0 V, I
REF
= 0.5 mA, C
COMP
= 47 F, TA = +25C unless otherwise noted.)
DAC16
REV. B
–3–
CAUTION
1. Stresses above those listed under “Absolute Maximum Rat­ings” may cause permanent damage to the device. This is a stress rating only and functional operation at or above this specification is not implied. Exposure to the above maximum rating conditions for extended periods may affect device reliability.
2. Digital inputs and outputs are protected; however, perma­nent damage may occur on unprotected units from high en­ergy electrostatic fields. Keep units in conductive foam or packaging at all times until ready to use. Use proper anti­static handling procedures.
3. Remove power before inserting or removing units from their sockets.
PIN CONFIGURATION
24-Lead DIP (P, S)
TOP VIEW
(Not to Scale)
24 23 22 21 20 19 18 17 16 15 14 13
1 2 3 4 5 6 7 8
9 10 11 12
DAC16
I
REF
C
COMP
DGND
V
CC
DB15 (MSB)
DB14 DB13 DB12 DB11 DB10
DB9 DB8 DB7
I
OUT
AGND REF GND V
EE
DB0 (LSB) DB1 DB2 DB3 DB4 DB5 DB6
PIN DESCRIPTION
Pin (P, S) Name Description
1I
REF
Reference Current Input 2 DGND Digital Ground 3V
CC
+5 V Digital Supply 4–19 DB15–DB0 16-Bit Digital Input Bus. DB15 is the MSB. 20 V
EE
–15 V Analog Supply 21 REF GND Reference Current Return 22 AGND Analog Ground/Output Reference 23 I
OUT
Current Output 24 C
COMP
Current Ladder Compensation
ORDERING GUIDE
Model Grade DNL (max) Temperature Ranges Package Descriptions Package Options
DAC16GS ±10°C to +70°C 24-Lead SOL R-24 DAC16FP ±2 –40°C to +85°C 24-Lead PDIP N-24 DAC16FS ±2 –40°C to +85°C 24-Lead SOL R-24 DAC16GBC ±1 +25°CDie
ABSOLUTE MAXIMUM RATINGS
(T
A
= +25°C unless otherwise noted)
VCC to VEE . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V, +25.0 V
V
CC
to DGND . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V, +7.0 V
V
EE
to AGND . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V, –18.0 V
DGND to AGND . . . . . . . . . . . . . . . . . . . . . . –0.3 V, +0.3 V
REF GND to AGND . . . . . . . . . . . . . . . . . . . –0.3 V, +1.0 V
I
REF
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 mA
Analog Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . 8 mA
Digital Input Voltage to DGND . . . . . . . . . . . . . . . . . . . ≤V
CC
Operating Temperature Range
FP, FS . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C
GS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
Dice Junction Temperature . . . . . . . . . . . . . . . . . . . . . +150°C
Storage Temperature . . . . . . . . . . . . . . . . . . –65°C to +150°C
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 mW
Lead Temperature (Soldering, 60 sec) . . . . . . . . . . . . +300°C
Package Type θ
JA
1
θ
JC
Units
24-Lead Plastic DIP (P) 62 32 °C/W 24-Lead Plastic SOL (S) 70 22 °C/W
NOTE
1
θJA is specified for worst case mounting conditions, i.e., θ
JA
is specified for
device in socket.
DICE CHARACTERISTICS
VCCDGND I
REF
C
COMP
I
OUT
AGND
REF GND
V
EE
DB0 (LSB)
DB1 DB2
DB3
DB4DB5DB6DB7DB8DB9
DB10
DB11
DB12
DB13
DB14
DB15 (MSB)
Die Size 0.129 x 0.153 inch, 19,737 sq. mils (3.277 x 3.886 mm, 12.73 sq. mm) The DAC16 Contains 330 Transistors. Substrate is V
EE
Polarity.
DAC16
REV. B
–4–
1 2 3 4 5 6 7 8
9 10 11 12
24 23 22 21 20 19 18 17 16 15 14 13
NC
10kV
+5V
–15V
Figure 2. Burn-In Diagram
OPERATION Novel DAC Architecture
The DAC16 was designed with a compound DAC architecture to achieve high accuracy, excellent linearity, and low transition errors. As shown in Figure 3, the DAC’s five most-significant bits utilize 31 identical segmented current sources to obtain optimal high speed settling at major code transitions. The lower nine bits utilize an inverted R-2R ladder network which is laser­trimmed to ensure excellent differential nonlinearity. The middle two bits (DB9 and DB10) arc binary-weighted and scaled from the MSB segments. Note that the flow of output current is into the DAC16—there is no signal inversion. As shown, the switches for each current source are essentially diodes. It is for this rea­son that the output voltage compliance of the DAC16 is limited to a few millivolts. The DAC16 was designed to operate with an operational amplifier configured as an I–V converter; therefore, the DAC16’s output must be connected to the sum node of an operational amplifier for proper operation. Exceeding the output voltage compliance of the DAC16 will introduce linearity errors. The reference current buffer assures full accuracy and fast set­tling by controlling the MSB reference node. The 16-bit paral­lel digital input is TTL/CMOS compatible and unbuffered,
minimizing the deleterious effects of digital feedthrough while allowing the user to tailor the digital interface to the speed requirements and bus configuration of the application.
Equivalent Circuit Analysis
An equivalent circuit for static operation of the DAC16 is illustrated in Figure 4. I
REF
is the current applied to the
DAC16 and is set externally to the device by V
REF
and
R
REF.
The output capacitance of the DAC16 is approxi­mately 10 pF and is code independent. Its output resis­tance R
O
is code dependent and is given by:
1
R
O
=
1
8 k
+
DB9
288 k
+
DB10
144 k
+
X
72 k
where
DB9 = State of Data Bit 9 = 0 or 1;
DB10 = State of Data Bit 10 = 0 or 1; and
X = Decimal representation of the 5 MSBs (DB11–DB15)
= 0 to 31.
I
DAC
R
O
C
O
I
OUT
I
OUT
= 8 • I
REF
RO = SEE TEXT C
O
= 10pF
65,535 Digital Code
65,536
Figure 4. Equivalent Circuit for the DAC16
Table I provides the relationship between the input digital code and the output resistance of the DAC16.
Table I. DAC16 Output Resistance vs. Digital Code
Hex Digital Code Scale Output Resistance
FFFF Zero 8 k BFFF 1/4 4.2 k 7FFF 1/2 2.9 k 3FFF 3/4 2.2 k 0 Full – 1 LSB 1.8 k
+5V
DB0 – DB15
SWITCH DETAIL
FROM SWITCH DECODER
4kV 4kV
8kV8kV
DB0 – DB8
4kV 4kV
4kV
SW10 SW9
SW8 SW7 SW6 SW0SW SW
SW
SW
18kV
31 CURRENT SOURCES
125mA EACH
DB11 – DB15
DB10 DB9
9 CURRENT SOURCES
15.63mA EACH
I
REF
I
OUT
AGND
C
COMP
62.5mA 31.25mA
Figure 3. DAC16 Architecture
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