TYPICAL PERFORMANCE CURVES (Cont.)
At TA = +25°C, VCC = +5V, fSAMPLE = 500kHz, fCLK = 16 • fSAMPLE, and internal +2.5V reference, unless otherwise specified.
SIGNAL-TO-NOISE RATIO and
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 247kHz, –0.2dB)
SIGNAL-TO-(NOISE+DISTORTION)
vs INPUT FREQUENCY
0
–20
76
74
72
70
68
66
64
SNR
–40
SINAD
–60
–80
–100
–120
0
62.5
125
187.5
250
1k
10k
100k
1M
Input Frequency (Hz)
Frequency (kHz)
SPURIOUS FREE DYNAMIC RANGE AND
TOTAL HARMONIC DISTORTION
vs INPUT FREQUENCY
CHANGE IN SIGNAL-TO-NOISE RATIO
and SIGNAL-TO-(NOISE+DISTORTION)
vs TEMPERATURE
90
85
80
75
70
65
–90
–85
–80
–75
–70
–65
0.3
0.2
SFDR
SNR
THD❉
0.1
0.0
SINAD
–0.1
–0.2
–0.3
❉ First nine harmonics
of the input frequency
fIN = 100kHz, –0.2dB
–40
–20
0
20
40
60
80
100
1k
10k
100k
1M
Temperature (°C)
Input Frequency (Hz)
CHANGE IN SPURIOUS FREE DYNAMIC RANGE
AND TOTAL HARMONIC DISTORTION
vs TEMPERATURE
1.0
0.5
–1.0
–0.5
0.0
fIN = 100kHz, –0.2dB
0.0
THD❉
–0.5
–1.0
–1.5
–2.0
0.5
SFDR
1.0
1.5
❉ First nine harmonics
of the input frequency
2.0
–40
–20
0
20
40
60
80
100
Temperature (°C)
®
ADS7818
6