Datasheet

AD7687 Data Sheet
Rev. B | Page 10 of 28
TYPICAL PERFORMANCE CHARACTERISTICS
CODE
INL (LSB)
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
0 16384 32768 49152 65535
02972-001
POSITIVE INL = +0.32LSB
NEGATIVE INL = –0.41LSB
Figure 7. Integral Nonlinearity vs. Code
02972-007
COUNTS
300000
250000
150000
200000
100000
50000
0
CODE IN HEX
45 46 4741 42 43 44
0 0 1049 0 0
258680
1391
VDD = REF = 5V
Figure 8. Histogram of a DC Input at the Code Center
FREQUENCY (kHz)
AMPLITUDE (dB of Full Scale)
0
–20
–40
–60
–80
–100
–120
–160
–140
–180
0 20 40 60 80 100 120
02972-008
8192 POINT FFT
VDD = REF = 5V
F
S
= 250KSPS
F
IN
= 2.1kHz
SNR = 95.5dB
THD = –118.3dB
2nd HARM = –130dB
3rd HARM = –122.7dB
Figure 9. FFT Plot
CODE
DNL (LSB)
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
0 16384 32768 49152 65535
02972-009
POSITIVE DNL = +0.27LSB
NEGATIVE DNL = –0.24LSB
Figure 10. Differential Nonlinearity vs. Code
02972-010
COUNTS
250000
150000
200000
100000
50000
0
CODE IN HEX
49 4A 4C44 46 47 48
0
45
060
30721
18
4B
00
200403
29918
VDD = REF = 2.5V
Figure 11. Histogram of a DC Input at the Code Center
FREQUENCY (kHz)
AMPLITUDE (dB of Full Scale)
0
–20
–40
–60
–80
–100
–120
–160
–140
–180
0 20 40 60 80 100 120
02972-011
32768 POINT FFT
VDD = REF = 2.5V
F
S
= 250KSPS
F
IN
= 2kHz
SNR = 92.8dB
THD = –115.9dB
2nd HARM = –124dB
3rd HARM = –119dB
Figure 12. FFT Plot