Datasheet

DAC SPECIFICATIONS
Parameter B Versions
2
Units Conditions/Comments
ACCURACY
Resolution 16 Bits
Monotonicity 16 Bits min
Integral Nonlinearity ± 0.01 % of FS max FS = Full-Scale Output Current
Offset (4 mA) @ +25°C
4
± 0.1 % of FS max V
CC
= 5 V
Offset Drift ± 25 ppm of FS/°C max Includes On-Chip Reference Drift
Total Output Error (20 mA) @ +25°C
4
± 0.2 % of FS max V
CC
= 5 V
Total Output Drift ± 50 ppm of FS/°C max Includes On-Chip Reference Drift
V
CC
Supply Sensitivity 50 nA/mV max 25 nA/mV Typical
VOLTAGE REFERENCE
REF OUT2
Output Voltage 2.49/2.51 V min/V max 2.5 V Nominal
Drift ± 40 ppm/°C max 20 ppm/°C Typical from –40°C to +25°C and
–2.5 ppm/°C Typical from +25°C to +85°C
Externally Available Current 0.5 mA min
V
CC
Supply Sensitivity 150 µV/V max 15 µV/V Typical
Output Impedance 3 Ω typ
Noise (0.1 Hz–10 Hz) 6 µV (p-p) typ
REF OUT1
Output Voltage 1.24/1.26 V min/V max 1.25 V Nominal, 100 kΩ Load to COM
5
Drift ± 50 ppm/°C max 20 ppm/°C Typical from –40°C to +25°C and
2 ppm/°C Typical from +25°C to +85°C
Externally Available Current 0.5 mA min
V
CC
Supply Sensitivity 150 µV/V max 15 µV/V Typical
Output Impedance 3 Ω typ
Noise (0.1 Hz–10 Hz) 4 µV (p-p) typ
REF IN
Input Resistance 40 kΩ typ
DIGITAL INPUTS
V
IH
(Logic 1) 0.75 × V
CC
V min
V
IL
(Logic 0) 0.25 × V
CC
V max
I
IH
± 10 µA max V
IN
= V
CC
I
IL
± 10 µA max V
IN
= 0 V
Data Coding Binary
Data Rate 10 Mbps max
POWER SUPPLIES
Operating Range +2.95 to +5.05 V min to V max Functional to 7 V
Quiescent Current
@ V
CC
= 3 V 650 µA max 475 µA Typical
@ V
CC
= 5 V 750 µA max 575 µA Typical
NOTES
1
The DN25D is available from Supertex, Inc., 1350 Bordeaux Drive, Sunnyvale, CA 94089.
2
Temperature range is –40°C to +85°C.
3
The max current loop voltage compliance is determined by the pass transistor breakdown voltage and is 350 V for the DN25D.
4
With V
CC
= 3 V, the transfer function shifts negative by typically 0.25%; a 16 kΩ resistor connected between COM and LOOPRTN will approximately compensate for the V
CC
supply sensitivity in moving from 5 V to 3 V by skewing the gain of the AD421.
5
100 kΩ resistor only required if this reference is being used in application circuits.
Specifications subject to change without notice.
AD421–LOOP-POWERED SPECIFICATIONS
Parameter B Versions
2
Units Conditions/Comments
OUTPUT CHARACTERISTICS
Current Loop Voltage Compliance
3
V
CC
+ 2 V min
350 V max DN25D Breakdown Voltage
Full-Scale Settling Time 8 ms typ Settling Time to ±0.1%, C1 = C2 = 10 nF, C3 = 3.3 nF
Output Impedance 25 MΩ typ
AC Loop Voltage Sensitivity 2 µA/V typ 1200 Hz to 2200 Hz
VOLTAGE REGULATOR
Output Voltage (V
CC
)
3 V Mode 2.95/3.05 V min/V max 3 V Nominal. LV Pin Connected to V
CC
3.3 V Mode 3.25/3.35 V min/V max 3.3 V Nominal. LV Pin Connected Through 0.01 µF to V
CC
5 V Mode 4.95/5.05 V min/V max 5 V Nominal. LV Pin Connected to COM
Externally Available Current 3.25 mA min Assuming 4 mA Flowing in the Loop
Line Regulation 1 µV/V typ
Load Regulation 15 µV/mA typ
–2–
(Using DN25D
1
as pass transistor as per Figure 3;
REF IN = REF OUT2; T
A
= T
MIN
to T
MAX
unless otherwise noted)
REV. C
(V
CC
= +3 V to +5 V; REF IN = REF OUT2; T
A
= T
MIN
to T
MAX
unless otherwise noted)