Datasheet

Figure 26. Power-Supply Grounding
Figure 27. V
SS
Power-Supply Rejection vs. Frequency
Figure 28. V
DD
Power-Supply Rejection vs. Frequency
Figure 29. MAX121 FFT Plot
FREQUENCY (Hz)
V
SS
REJECTION (dB)
100k
40
50
60
30
10k 1M
T
A
= +25°C
FREQUENCY (kHz)
SIGNAL AMPLITUDE (dB)
10050
-120
-100
-80
-60
-40
-20
0
0 150
f
S
= 300kHz
I
IN
= 50kHz
T
A
= +25°C
SINAD = 78dB
-15V
-15V-15V
AGND
ANALOG
SUPPLY
DIGITAL
SUPPLY
DIGITAL
CIRCUITRY
+5V DGND
OPTIONAL
5Ω FILTER
RESISTOR
DGND
MAX121
+5V
+5VAGND DGND
FREQUENCY (Hz)
V
DD
REJECTION (dB)
100k
30
40
50
60
20
10k 1M
T
A
= +25°C
WITH PI FILTER
NO PI FILTER
0.1µF
TO
MAX121
V
DD
PIN
V
DD
+5V
10µF
5Ω
PI FILTER
MAX121 308ksps ADC with DSP Interface and 78dB SINAD
www.maximintegrated.com
Maxim Integrated │ 23