AD8221
0.80
0.75
180
160
GAIN = 1000
140
V
S
= ±15V
INPUT BIAS CURRENT (nA)
0.70
0.65
0.60
0.55
0.50
0.45
0.40
–15
POSITIVE PSRR (dB)
GAIN = 100
GAIN = 10
GAIN = 1
120
100
80
60
40
GAIN = 1000
V
S
= ±5V
COMMON-MODE VOLTAGE (V)
FREQUENCY (Hz)
Figure 9. I
BIAS
vs. CMV
Figure 12. Positive PSRR vs. Frequency, RTI (G = 1 to 1000)
2.00
180
160
GAIN = 1000
140
NEGATIVE PSRR (dB)
CHANGE IN INPUT OFFSET VOLTAGE (µV)
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0
0.01
GAIN = 100
120
100
80
60
40
20
0.1
GAIN = 10
GAIN = 1
03149-012
–10
–5
0
5
10
15
03149-009
20
0.1
1
10
100
1k
10k
100k
1M
0.1
1
10
03149-010
1
10
100
1k
10k
100k
1M
WARM-UP TIME (min)
FREQUENCY (Hz)
Figure 10. Change in Input Offset Voltage vs. Warm-Up Time
Figure 13. Negative PSRR vs. Frequency, RTI (G = 1 to 1000)
5
4
3
VS = ±15V
100k
TOTAL DRIFT 25°C – 85°C RTI (µV)
INPUT CURRENT (nA)
2
1
0
–1
–2
–3
–4
–20
0
20
40
60
80
100
120
140
03149-011
10k
BEST AVAILABLE FET
INPUT IN-AMP GAIN = 1
1k
BEST AVAILABLE FET
INPUT IN-AMP GAIN = 1000
INPUT OFFSET CURRENT
INPUT BIAS CURRENT
100
AD8221 GAIN = 1
AD8221 GAIN = 1000
03149-014
–5
–40
10
10
100
1k
10k
100k
1M
10M
TEMPERATURE (°C)
SOURCE RESISTANCE (Ω)
Figure 11. Input Bias Current and Offset Current vs. Temperature
Figure 14. Total Drift vs. Source Resistance
Rev. B | Page 10 of 24
03149-013
AD [ ANALOG DEVICES ]
