AD7768 Datasheet, PDF (34/99 Pages) Analog Devices – 8-/4-Channel, 24-Bit, Simultaneous Sampling ADCs with Power Scaling, 110.8 kHz BW

AD7768/AD7768-4
0
–20
–40
–60
–80
–100
FAST
MEDIAN
ECO
–120
–140
–160
–180
10
100
1k
10k
INPUT FREQUENCY (Hz)
100k
Figure 36. THD vs. Input Frequency, Three Power Modes, Sinc5 Filter
0
FAST THD
–20
FAST THD + N
MEDIAN THD
–40
MEDIAN THD + N
ECO THD
ECO THD + N
–60
f_IN = 1kHz
–80
–100
–120
–140
–160
–180
–140 –120 –100 –80
–60
–40
–20
0
INPUT AMPLITUDE (dBFS)
Figure 37. THD and THD + N vs. Input Amplitude, Wideband Filter
0
FAST THD
–20
FAST THD + N
MEDIAN THD
MEDIAN THD + N
–40
ECO THD
ECO THD + N
–60
f_IN = 1kHz
–80
–100
–120
–140
–160
–180
–140 –120 –100 –80
–60
–40
–20
0
INPUT AMPLITUDE (dBFS)
Figure 38. THD and THD + N vs. Input Amplitude, Sinc5 Filter
Data Sheet
120
FAST MODE, SINC5 FILTER
118
FAST MODE, WIDEBAND FILTER
MEDIAN MODE, SINC5 FILTER
MEDIAN MODE, WIDEBAND FILTER
116
ECO MODE, SINC5 FILTER
ECO MODE, WIDEBAND FILTER
114
112
110
108
106
104
102
100
–140 –120 –100 –80
–60
–40
–20
0
INPUT AMPLITUDE (dBFS)
Figure 39. SNR vs. Input Amplitude
4
3
V_REF = 2.500V
2
V_REF = 4.096V
V_REF = 5.000V
1
0
–1
–2
–3
–4
–V_REF
0V
INPUT VOLTAGE (V)
+V_REF
Figure 40. INL Error vs. Input Voltage for Various Voltage Reference (VREF)
Levels, Fast Mode
4
3
V_REF = 2.500V
2
V_REF = 4.096V
V_REF = 5.000V
1
0
–1
–2
–3
–4
–V_REF
0V
INPUT VOLTAGE (V)
+V_REF
Figure 41. INL Error vs. Input Voltage for Various Voltage Reference (VREF)
Levels, Median Mode
Rev. A | Page 34 of 99