Datasheet

AD7912/AD7922
Rev. 0 | Page 13 of 32
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 10 and Figure 11 show typical FFT plots for the AD7922
and AD7912, respectively, at a 1 MSPS sample rate and 100 kHz
input frequency.
Figure 12 shows the SINAD performance versus the input
frequency for various supply voltages while sampling at 1 MSPS
with a SCLK frequency of 18 MHz for the AD7922.
Figure 13 shows the SNR performance versus the input fre-
quency for various supply voltages while sampling at 1 MSPS
with an SCLK frequency of 18 MHz for the AD7922.
Figure 14 and Figure 15 show INL and DNL performance for
the AD7922.
Figure 16 shows a graph of the THD versus the analog input
frequency for different source impedances when using a supply
voltage of 3.6 V and a sampling rate of 1 MSPS. See the Analog
Input section.
Figure 17 shows a graph of the THD versus the analog input
frequency for various supply voltages while sampling at 1 MSPS
with an SCLK frequency of 18 MHz.
Figure 18 shows the shutdown current versus the voltage supply
for different operating temperatures.
5
–15
–35
–55
–75
–95
–115
0 50 100 150 200 250 300 350 400 450 500
04351-0-040
SNR (dB)
FREQUENCY (kHz)
8192 POINT FFT
V
DD
= 2.7V
F
SAMP
= 1MSPS
F
IN
= 100kHz
SNR = 73.1dB
SINAD = 72.55dB
THD = –81.78dB
SFDR = –83.03dB
Figure 10. AD7922 Dynamic Performance at 1 MSPS
–10
–30
–50
–70
–90
–110
0 50 100 150 200 250 300 350 400 450 500
04351-0-041
SNR (dB)
FREQUENCY (kHz)
8192 POINT FFT
V
DD
= 2.7V
F
SAMP
= 1MSPS
F
IN
= 100kHz
SNR = 61.88dB
SINAD = 61.83dB
THD = –81.12dB
SFDR = –84.92dB
Figure 11. AD7912 Dynamic Performance at 1 MSPS
–67
–74
–73
–72
–71
–70
–69
–68
10 100 1000
04351-0-043
SINAD (dB)
FREQUENCY (kHz)
V
DD
= 2.7V
V
DD
= 2.35V
V
DD
= 5.25V
V
DD
= 4.75V
V
DD
= 3.6V
Figure 12. AD7922 SINAD vs. Input Frequency at 1 MSPS
–71.6
–71.8
–72.0
–72.4
–72.2
–72.6
–72.8
–73.0
–73.2
–73.4
–73.6
10 100 1000
04351-0-044
SNR (dB)
FREQUENCY (kHz)
V
DD
= 2.35V
V
DD
= 5.25V
V
DD
= 2.7V
V
DD
= 4.75V
V
DD
= 3.6V
Figure 13. AD7922 SNR vs. Input Frequency at 1 MSPS