AD7922 Analog Devices, AD7922 Datasheet - Page 13

• Manufacturer Part Number: AD7922
• Description: 2-Channel, 2.35 V to 5.25 V, 1 MSPS, 12-Bit A/D Converter
• Manufacturer: Analog Devices

Specifications of AD7922

• Resolution (bits): 12bit
• # Chan: 2
• Sample Rate: 1MSPS
• Interface: Ser,SPI
• Analog Input Type: SE-Uni
• Ain Range: Uni Vdd
• Adc Architecture: SAR
• Pkg Type: SOP,SOT

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.
–115
–110
–15
–35
–55
–75
–95
–10
–30
–50
–70
–90
5
0
0
Figure 10. AD7922 Dynamic Performance at 1 MSPS
Figure 11. AD7912 Dynamic Performance at 1 MSPS
50
50
100
100
150
150
FREQUENCY (kHz)
FREQUENCY (kHz)
200
200
250
250
300
300
350
350
8192 POINT FFT
V
F
F
SNR = 73.1dB
SINAD = 72.55dB
THD = –81.78dB
SFDR = –83.03dB
8192 POINT FFT
V
F
F
SNR = 61.88dB
SINAD = 61.83dB
THD = –81.12dB
SFDR = –84.92dB
SAMP
IN
SAMP
IN
DD
DD
= 100kHz
= 100kHz
400
400
= 2.7V
= 2.7V
= 1MSPS
= 1MSPS
450
450
500
500
Rev. 0 | Page 13 of 32
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.
–71.6
–71.8
–72.0
–72.2
–72.4
–72.6
–72.8
–73.0
–73.2
–73.4
–73.6
–67
–68
–69
–70
–71
–72
–73
–74
Figure 12. AD7922 SINAD vs. Input Frequency at 1 MSPS
10
10
Figure 13. AD7922 SNR vs. Input Frequency at 1 MSPS
V
DD
FREQUENCY (kHz)
= 2.7V
FREQUENCY (kHz)
100
100
V
V
DD
DD
V
DD
V
= 5.25V
= 5.25V
V
AD7912/AD7922
DD
V
DD
= 4.75V
DD
V
= 2.35V
= 3.6V
DD
= 2.35V
V
= 3.6V
DD
= 4.75V
V
DD
= 2.7V
1000
1000