Datasheet

AD7942
Rev. B | Page 9 of 24
TYPICAL PERFORMANCE CHARACTERISTICS
POSITIVE INL = +0.22LSB
NEGATIVE INL = –0.34LSB
1.00
0.75
0.50
0.25
0
–0.50
–0.75
–1.00
–0.25
INL (LSB)
0 4096 8192 12,288 16,384
CODE
04657-005
Figure 5. Integral Nonlinearity vs. Code
129,941
150,000
100,000
50,000
0
COUNTS
0 0 915 216 0 0
1FFD 1FFE
1FFF
2000 2001 2002 2003
CODE IN HEX
VDD = V
REF
= 2.5V
04657-006
Figure 6. Histogram of a DC Input at the Code Center
0
–20
–40
–60
–80
–100
–120
–140
–160
–180
AMPLITUDE (dB of Full Scale)
0 25 50 75 100 125
FREQUENCY (kHz)
16,384 POINT FFT
VDD = V
REF
= 5V
f
S
= 250kSPS
f
IN
= 20.43kHz
SNR = 85.1dB
THD = –105dB
SFDR = –105.9dB
04657-007
Figure 7. FFT Plot
POSITIVE DNL = +0.24LSB
NEGATIVE DNL = –0.12LSB
1.00
0.75
0.50
0.25
0
–0.50
–0.75
–1.00
–0.25
DNL (LSB)
0 4096 8192 12,288 16,384
CODE
04657-008
Figure 8. Differential Nonlinearity vs. Code
150,000
100,000
50,000
0
COUNTS
000 0 00
1FFD 1FFE
1FFF
2000 2001 2002 2003
CODE IN HEX
VDD = V
REF
= 5V
131,072
04657-009
Figure 9. Histogram of a DC Input at the Code Center
0
–20
–40
–60
–80
–100
–120
–140
–160
–180
AMPLITUDE (dB of Full Scale)
0 25 50 75 100 125
FREQUENCY (kHz)
16,384 POINT FFT
VDD = V
REF
= 2.5V
f
S
= 250kSPS
f
IN
= 20.43kHz
SNR = 84.2dB
THD = –101.7dB
SFDR = –104.3dB
04657-010
Figure 10. FFT Plot