Datasheet

AD5421 Data Sheet
Rev. G | Page 16 of 36
0.0015
–0.0025
–0.0020
–0.0015
–0.0010
–0.0005
0
0.0005
0.0010
0 605040
30
2010
GAIN ERROR (% FSR)
LOOP SUPPLY VOLTAGE (V)
R
LOAD
= 250Ω
T
A
= 25°C
3.8mA TO 21mA RANGE
EXT V
REF
EXT R
SET
09128-017
Figure 19. Gain Error vs. Loop Supply Voltage
0.0030
0.0025
0.0020
0.0015
0.0010
0.0005
0
–0.0005
0
605040
302010
FULL-SCALE ERROR (% FSR)
LOOP SUPPLY VOLTAGE (V)
R
LOAD
= 250Ω
T
A
= 25°C
3.8mA TO 21mA RANGE
EXT V
REF
EXT R
SET
09128-018
Figure 20. Full-Scale Error vs. Loop Supply Voltage
2000
0
250
500
750
1000
1250
1500
1750
0
5040302010
LOAD RESISTANCE (Ω)
LOOP SUPPLY VOLTAGE (V)
T
A
= 25°C
EXT V
REF
I
LOOP
= 24mA
EXT R
SET
OPERATING AREA
09128-019
Figure 21. Load Resistance Load Line vs. Loop Supply Voltage
(Voltage Between LOOP− and REG
IN
)
4.70
4.35
4.40
4.45
4.50
4.55
4.60
4.65
–40 10080
6040
200–20
COMPLIANCE VOLTAGE HEADROOM (V)
TEMPERATURE (°C)
R
LOAD
= 250Ω
3.2mA TO 24mA RANGE
EXT V
REF
I
LOOP
= 24mA
09128-020
Figure 22. Compliance Voltage Headroom vs. Temperature
7
6
5
4
3
2
1
0
0
5.04.5
4.0
3.53.0
2.52.01.51.0
0.5
LOOP CURRENT ERROR (µA)
REG
OUT
LOAD CURRENT (mA)
V
LOOP
= 24V
EXT NMOS
R
LOAD
= 250Ω
T
A
= 25°C
I
LOOP
= 20mA
09128-021
Figure 23. Loop Current Error vs. REG
OUT
Load Current
8
–8
–6
–4
–2
0
2
4
6
0 109876
54321
VOLTAGE ACROSS 250Ω LOAD RESISTOR
(µV)
TIME (Seconds)
V
LOOP
= 24V
EXT NMOS
EXT V
REF
I
LOOP
= 4mA
R
LOAD
= 250Ω
T
A
= 25°C
09128-022
Figure 24. Loop Current Noise, 0.1 Hz to 10 Hz Bandwidth