Datasheet

AD7910/AD7920
Rev. C | Page 10 of 24
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 7 and Figure 8 show a typical FFT plot for the AD7920 and
AD7910, respectively, at a 250 kSPS sampling rate and a 100 kHz
input frequency.
Figure 9 shows the signal-to-(noise + distortion) ratio performance
vs. input frequency for various supply voltages while sampling at
250 kSPS with an SCLK frequency of 5 MHz for the AD7920.
Figure 10 and Figure 11 show typical INL and DNL performance
for the AD7920.
Figure 12 shows a graph of the total harmonic distortion vs. analog
input frequency for different source impedances when using a
supply voltage of 3.6 V and sampling at a rate of 250 kSPS. See the
Analog Input section.
Figure 13 shows a graph of the total harmonic distortion vs.
analog input signal frequency for various supply voltages while
sampling at 250 kSPS with an SCLK frequency of 5 MHz.
FREQUENCY (kHz)
–5
–55
–115
0 12525
SNR (dB)
50 75 100
–15
–35
–75
–95
8192 POINT FFT
V
DD
= 2.7V
f
SAMPLE
= 250kSPS
f
IN
= 100kHz
SINAD = 72.05dB
THD = –82.87dB
SFDR = –87.24dB
02976-007
Figure 7. AD7920 Dynamic Performance at 250 kSPS
FREQUENCY (kHz)
–45
–105
SNR (dB)
–5
15
–25
–65
–85
0 12525 50 75 100
02976-008
8192 POINT FFT
V
DD
= 2.35V
f
SAMPLE
= 250kSPS
f
IN
= 100kHz
SINAD = 61.67dB
THD = –79.59dB
SFDR = –82.93dB
Figure 8. AD7910 Dynamic Performance at 250 kSPS
FREQUENCY (kHz)
–72.0
10 1000
SINAD (dB)
100
–73.0
–73.5
V
DD
= 5.25V
V
DD
= 2.35V
V
DD
= 2.7V
V
DD
= 4.75V
V
DD
= 3.6V
–72.5
–71.0
–71.5
02976-009
Figure 9. AD7920 SINAD vs. Input Frequency at 250 kSPS
CODE
1.0
0.4
–0.2
0 1024
INL ERROR (LSB)
512
0.8
0.6
0.2
0
–0.4
–0.6
–0.8
–1.0
1536 2048 2560 3072 3584 4096
V
DD
= 2.35V
TEMP = 25°C
f
SAMPLE
= 250kSPS
02976-010
Figure 10. AD7920 INL Performance