AD7691 Analog Devices, AD7691 Datasheet - Page 9

• Manufacturer Part Number: AD7691
• Manufacturer: Analog Devices

Specifications of AD7691

• Resolution (bits): 18bit
• # Chan: 1
• Sample Rate: 250kSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p
• Adc Architecture: SAR
• Pkg Type: CSP,SOP

TYPICAL PERFORMANCE CHARACTERISTICS
–0.5
–1.0
–1.5
–100
–120
–140
–160
–180
1.5
1.0
0.5
–20
–40
–60
–80
80k
70k
60k
50k
40k
30k
20k
10k
0
0
Figure 8. Histogram of a DC Input at the Code Center, 5 V
0
0
0
25
0
Figure 7. Integral Nonlinearity vs. Code 2.5 V
26
20
0
65536
27
Figure 9. 2 kHz FFT Plot, 5 V
26
2904
40
28
FREQUENCY (kHz)
28527
29
CODE IN HEX
131072
CODE
60
69769
2A
32768 POINT FFT
VDD = REF = 5V
f
f
SNR = 101.4dB
THD = –120.1dB
2ND HARMONIC = –140.7dB
3RD HARMONIC = –120.3dB
POSITIVE INL = 0.39LSB
NEGATIVE INL = –0.73LSB
S
IN
27770
= 250kSPS
2B
= 2kHz
80
2062
2C
196608
VDD = REF = 5V
σ = 0.76LSB
2D
100
14
2E
0
262144
120
2F
0
Rev. B | Page 9 of 28
–0.5
–1.0
–100
–120
–140
–160
–180
1.0
0.5
–20
–40
–60
–80
Figure 11. Histogram of a DC Input at the Code Center, 2.5 V
45k
40k
35k
30k
25k
20k
15k
10k
0
5k
0
0
0
0
23
0 12 29 501
Figure 10. Differential Nonlinearity vs. Code, 5 V
10
24
25 26
65536
Figure 12. 2 kHz FFT Plot, 2.5 V
20
2997
27
30
14362
FREQUENCY (kHz)
28 29
24411
CODE IN HEX
40
131072
CODE
38068
2A
POSITIVE DNL = 0.37LSB
NEGATIVE DNL = –0.33LSB
50
32768 POINT FFT
VDD = REF = 2.5V
f
f
SNR = 96.4dB
THD = –120.3dB
2ND HARMONIC = –132.5dB
3RD HARMONIC = –121.2dB
28179
S
IN
2B
= 180kSPS
= 2kHz
17460
2C 2D
60
196608
4055
VDD = REF = 2.5V
σ = 1.42LSB
910 78
70
2E
2F
80
AD7691
30 31
9
262144
0
90