Datasheet

AD7688
Rev. A | Page 9 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
02973-001
POSITIVE INL = +0.31LSB
NEGATIVE INL = –0.39LSB
Figure 7. Integral Nonlinearity vs. Code
02973-007
COUNTS
300000
250000
150000
200000
100000
50000
0
CODE IN HEX
73 74 756F 70 71 72
0 0 2930 0 0
256159
2031
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 25 50 75 100 125 150 200175 225 250
02973-008
16384 POINT FFT
VDD = REF = 5V
F
S
= 500KSPS
F
IN
= 2kHz
SNR = 95.6dB
THD = –117.7dB
SFDR = –117.9dB
2nd HARM = –125dB
3rd HARM = –119dB
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
02973-009
POSITIVE DNL = +0.37LSB
NEGATIVE DNL = –0.21LSB
Figure 10. Differential Nonlinearity vs. Code
02973-010
COUNTS
160000
120000
140000
100000
80000
40000
20000
60000
0
CODE IN HEX
74 7671 73
0
72
0
75
00
136187
124933
VDD = REF = 5V
Figure 11. Histogram of a DC Input at the Code Transition
02973-011
INPUT LEVEL (dB)
0–10–8–6–4–2
SNR (dB)
100
99
98
97
96
95
94
93
92
91
90
Figure 12. SNR vs. Input Level