Datasheet

AD9201
–12–
REV. D
COMMON-MODE LEVEL – V
–30
–35
–80
–0.5 1.50 0.5 1.0
–50
–65
–70
–75
–40
–45
–60
–55
THD – dB
1V SPAN
2V SPAN
a. Differential Input, 3 V Supplies
COMMON-MODE LEVEL – V
–30
–35
–80
–0.5 2.50 0.5 1.0
–50
–65
–70
–75
–40
–45
–60
–55
THD – dB
1.5 2.0
1V SPAN
2V SPAN
b. Differential Input, 5 V Supplies
COMMON-MODE LEVEL – V
–10
–80
–0.5 0 0.5 1.0
–40
–60
–70
–20
–30
–50
THD – dB
1.5
1V SPAN
2V SPAN
c. Single-Ended Input, 3 V Supplies
COMMON-MODE LEVEL – V
–10
–80
–0.5 2.50 0.5 1.0
–40
–60
–70
–20
–30
–50
THD – dB
1.5 2.0
1V SPAN
2V SPAN
d. Single-Ended Input, 5 V Supplies
Figure 29. THD vs. CML Input Span and Power Supply (Analog Input = 1 MHz)
COMMON-MODE PERFORMANCE
Attention to the common-mode point of the analog input volt-
age can improve the performance of the AD9201. Figure 29
illustrates THD as a function of common-mode voltage (center
point of the analog input span) and power supply.
Inspection of the curves will yield the following conclusions:
1. An AD9201 running with AVDD = 5 V is the easiest to
drive.
2. Differential inputs are the most insensitive to common-mode
voltage.
3. An AD9201 powered by AVDD = 3 V and a single ended
input, should have a 1 V span with a common-mode voltage
of 0.75 V.