Texas Instruments ADS867 Series Manual page 17

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Typical Characteristics (continued)
At T = 25°C, AVDD = 5 V, DVDD = 3 V, internal reference V
A
0.05
0.03
0.01
-0.01
---- ± 2.5*V
---- “ 0.625*V
-------“0.156 V
-0.03
---- + 1.25*V
---- + 0.3125*V
-0.05
±40 ±7
Free-Air Temperature (
Figure 38. Gain Error vs Temperature Across Input Ranges
0.05
0.03
0.01
-0.01
-0.03
-0.05
±40 ±7
Free- Air Temperature (
Range = ±2.5 × V
Figure 40. Gain Error vs Temperature Across Channels
0
±40
±80
±120
±160
0 50000 100000
Input Frequency (Hz)
Number of points = 16k, f
SINAD = 85.35, THD = –104.68 dB, SFDR = 105 dB
Figure 42. Typical FFT Plot (±2.5 × V
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---- “ 1.25*V
REF, REF
------“0.3125*V
REF, REF
---- + 2.5*V
REF, REF
---- + 0.625*V
REF, REF
REF
26 59 92 125
o
C)
C039
......CH0, .......CH1, ......CH2,
.......CH3, ......CH4, .......CH5,
........CH6, .......CH7
26 59 92 125
o
C)
C041
REF
150000 200000 250000
C043
= 1 kHz, SNR = 85.37 dB,
IN
)
REF
Product Folder Links:
= 4.096 V, and f = 500 kSPS, unless otherwise noted.
REF SAMPLE
140
120
100
80
60
40
20
0
0 0.5 1
Range = ±2.5 × V
Figure 39. Typical Histogram for Gain Error Drift
2
---- ± 2.5*V
REF,
---- ] 0.625*V
REF,
-------]0.156 V
REF,
1.5 ---- + 1.25*V
REF,
---- + 0.3125*V
1
0.5
0
0 4
Figure 41. Gain Error vs External Resistance (R
0
±40
±80
±120
±160
0 50000
Number of points = 16k, f
SINAD = 85.15 dB, THD = –105.28 dB, SFDR = 105 dB
Figure 43. Typical FFT Plot (±1.25 × V
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ADS8674 ADS8678
ADS8674, ADS8678
SBAS627 – JULY 2015
1.5 2 2.5 3 3.5
o
Gain Drift (ppm/ C)
REF
---- ] 1.25*V
REF
------]0.3125*V
REF
---- + 2.5*V
REF
---- + 0.625*V
REF
REF
8 12 16
Source Resistance (k )
100000 150000 200000
Input Frequency (Hz)
= 1 kHz, SNR = 85.11 dB,
IN
)
REF
4
C040
20
C042
)
EXT
250000
C044
17