Datasheet

Data Sheet AD7691
Rev. C | Page 9 of 28
TYPICAL PERFORMANCE CHARACTERISTICS
1.5
–1.5
0 262144
CODE
INL (LSB)
1.0
0.5
0
–0.5
–1.0
65536 131072 196608
POSITIVE INL = 0.39LSB
NEGATIVE INL = –0.73LSB
06146-026
Figure 7. Integral Nonlinearity vs. Code 2.5 V
80k
0
25
CODE IN HEX
COUNTS
70k
60k
50k
40k
30k
20k
10k
26 27 28 29 2A 2B 2C 2D 2E 2F
0
0
26
2062
14
0 0
2904
69769
28527
27770
VDD = REF = 5V
σ = 0.76LSB
06146-027
Figure 8. Histogram of a DC Input at the Code Center, 5 V
0
–180
0
FREQUENCY (kHz)
AMPLITUDE (dB of Full Scale)
–20
–40
–60
–80
–100
–120
–140
–160
20 40 60 80 100 120
32768 POINT FFT
VDD = REF = 5V
f
S
= 250kSPS
f
IN
= 2kHz
SNR = 101.4dB
THD = –120.1dB
2ND HARMONIC = –140.7dB
3RD HARMONIC = –120.3dB
06146-028
Figure 9. 2 kHz FFT Plot, 5 V
1.0
–1.0
0 262144
CODE
DNL (LSB)
0.5
0
–0.5
65536 131072 196608
POSITIVE DNL = 0.37LSB
NEGATIVE DNL = –0.33LSB
06146-029
Figure 10. Differential Nonlinearity vs. Code, 5 V
45k
0
CODE IN HEX
COUNTS
2423 25 26 28 29 2B2A 2C 2D 2F2E 30 31
01229
501
910
78 9 0
17460
28179
VDD = REF = 2.5V
σ = 1.42LSB
14362
24411
27
2997
38068
06146-030
40k
35k
30k
25k
20k
15k
10k
5k
4055
Figure 11. Histogram of a DC Input at the Code Center, 2.5 V
0
–180
0
FREQUENCY (kHz)
AMPLITUDE (dB of Full Scale)
–20
–40
–60
–80
–100
–120
–140
–160
2010 30 40 50 60 70 80 90
32768 POINT FFT
VDD = REF = 2.5V
f
S
= 180kSPS
f
IN
= 2kHz
SNR = 96.4dB
THD = –120.3dB
2ND HARMONIC = –132.5dB
3RD HARMONIC = –121.2dB
06146-031
Figure 12. 2 kHz FFT Plot, 2.5 V