Datasheet

AD7680
Rev. A | Page 10 of 24
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 5 shows a typical FFT plot for the AD7680 at 100 kSPS
sample rate and 10 kHz input frequency. Figure 6 shows the
signal-to-(noise + distortion) ratio performance versus the
input frequency for various supply voltages while sampling at
100 kSPS with an SCLK of 2.5 MHz.
Figure 7 shows a graph of the total harmonic distortion versus
the analog input frequency for various supply voltages, while
Figure 8 shows a graph of the total harmonic distortion versus
the analog input frequency for various source impedances (see
the Analog Input section). Figure 9 and Figure 10 show the
typical INL and DNL plots for the AD7680.
03643-0-021
dB
–140
–120
–100
–80
–60
–40
–20
–160
0 10k 20k 30k 40k
FREQUENCY (kHz)
50k
0
V
DD
= 5V
F
SAMPLE
= 100kSPS
F
IN
= 10kHz
SNR = 88.28dB
SINAD = 87.82dB
THD = –97.76dB
SFDR = –98.25dB
Figure 5. AD7680 Dynamic Performance at 100 kSPS
03643-0-016
SINAD (dB)
80
10
INPUT FREQUENCY (kHz)
100
85
90
95
V
DD
= 2.5V
V
DD
= 5.25V
V
DD
= 4.75V
V
DD
= 4.3V
V
DD
= 3.6V
V
DD
= 3.0V
V
DD
= 2.7V
F
SAMPLE
= 100kSPS
T
A
= 25°C
Figure 6. AD7680 SINAD vs. Analog Input Frequency
for Various Supply Voltages at 100 kSPS
03643-0-017
THD (dB)
90
10
INPUT FREQUENCY (kHz)
100
100
95
105
110
V
DD
= 4.75V
V
DD
= 4.3V
V
DD
= 3.6V
V
DD
= 3.0V
V
DD
= 2.7V
V
DD
= 2.5V
V
DD
= 5.25V
F
SAMPLE
= 100kSPS
T
A
= 25°C
Figure 7. AD7680 THD vs. Analog Input Frequency
for Various Supply Voltages at 100 kSPS
03643-0-018
THD (dB)
75
10
INPUT FREQUENCY (kHz)
100
95
100
80
90
85
105
110
F
SAMPLE
= 100kSPS
T
A
= 25°C
V
DD
= 4.75V
R
IN
= 10Ω
R
IN
= 50Ω
R
IN
= 100Ω
R
IN
= 1000Ω
Figure 8. AD7680 THD vs. Analog Input Frequency
for Various Source Impedances