AD421–LOOP-POWERED SPECIFICATIONS
Parameter
OUTPUT CHARACTERISTICS
Current Loop Voltage Compliance
3
Full-Scale Settling Time
Output Impedance
AC Loop Voltage Sensitivity
VOLTAGE REGULATOR
Output Voltage (V
CC
)
3 V Mode
3.3 V Mode
5 V Mode
Externally Available Current
Line Regulation
Load Regulation
B Versions
2
V
CC
+ 2
350
8
25
2
Units
V min
V max
ms typ
MΩ typ
µA/V
typ
(Using DN25D
1
as pass transistor as per Figure 3;
REF IN = REF OUT2; T
A
= T
MIN
to T
MAX
unless otherwise noted)
Conditions/Comments
DN25D Breakdown Voltage
Settling Time to
±
0.1%, C1 = C2 = 10 nF, C3 = 3.3 nF
1200 Hz to 2200 Hz
2.95/3.05
3.25/3.35
4.95/5.05
3.25
1
15
V min/V max
V min/V max
V min/V max
mA min
µV/V
typ
µV/mA
typ
3 V Nominal. LV Pin Connected to V
CC
3.3 V Nominal. LV Pin Connected Through 0.01
µF
to V
CC
5 V Nominal. LV Pin Connected to COM
Assuming 4 mA Flowing in the Loop
DAC SPECIFICATIONS
(V
Parameter
ACCURACY
Resolution
Monotonicity
Integral Nonlinearity
Offset (4 mA) @ +25°C
4
Offset Drift
Total Output Error (20 mA) @ +25°C
4
Total Output Drift
V
CC
Supply Sensitivity
VOLTAGE REFERENCE
REF OUT2
Output Voltage
Drift
Externally Available Current
V
CC
Supply Sensitivity
Output Impedance
Noise (0.1 Hz–10 Hz)
REF OUT1
Output Voltage
Drift
Externally Available Current
V
CC
Supply Sensitivity
Output Impedance
Noise (0.1 Hz–10 Hz)
REF IN
Input Resistance
DIGITAL INPUTS
V
IH
(Logic 1)
V
IL
(Logic 0)
I
IH
I
IL
Data Coding
Data Rate
POWER SUPPLIES
Operating Range
Quiescent Current
@ V
CC
= 3 V
@ V
CC
= 5 V
NOTES
1
2
CC
= +3 V to +5 V; REF IN = REF OUT2; T
A
= T
MIN
to T
MAX
unless otherwise noted)
B Versions
2
16
16
±
0.01
±
0.1
±
25
±
0.2
±
50
50
Units
Bits
Bits min
% of FS max
% of FS max
ppm of FS/°C max
% of FS max
ppm of FS/°C max
nA/mV max
Conditions/Comments
FS = Full-Scale Output Current
V
CC
= 5 V
Includes On-Chip Reference Drift
V
CC
= 5 V
Includes On-Chip Reference Drift
25 nA/mV Typical
2.49/2.51
±
40
0.5
150
3
6
1.24/1.26
±
50
0.5
150
3
4
40
0.75
×
V
CC
0.25
×
V
CC
±
10
±
10
Binary
10
+2.95 to +5.05
650
750
V min/V max
ppm/°C max
mA min
µV/V
max
Ω
typ
µV
(p-p) typ
V min/V max
ppm/°C max
mA min
µV/V
max
Ω
typ
µV
(p-p) typ
kΩ typ
V min
V max
µA
max
µA
max
Mbps max
V min to V max
µA
max
µA
max
2.5 V Nominal
20 ppm/°C Typical from –40°C to +25°C and
–2.5 ppm/°C Typical from +25°C to +85°C
15
µV/V
Typical
1.25 V Nominal, 100 kΩ Load to COM
5
20 ppm/°C Typical from –40°C to +25°C and
2 ppm/°C Typical from +25°C to +85°C
15
µV/V
Typical
V
IN
= V
CC
V
IN
= 0 V
Functional to 7 V
475
µA
Typical
575
µA
Typical
The DN25D is available from Supertex, Inc., 1350 Bordeaux Drive, Sunnyvale, CA 94089.
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.
–2–
REV. C
AD [ ANALOG DEVICES ]
