MAX1182 Maxim Integrated Products, MAX1182 Datasheet - Page 18

• Manufacturer Part Number: MAX1182
• Description: Low-Power ADC
• Manufacturer: Maxim Integrated Products

Dual 10-Bit, 65Msps, 3V, Low-Power ADC with
Internal Reference and Parallel Outputs
For a waveform perfectly reconstructed from digital
samples, the theoretical maximum SNR is the ratio of the
full-scale analog input (RMS value) to the RMS quantiza-
tion error (residual error). The ideal, theoretical minimum
analog-to-digital noise is caused by quantization error
only and results directly from the ADC’s resolution
(N-Bits):
Figure 7. Using an Op Amp for Single-Ended, AC-Coupled Input Drive
18
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SNR
dB[max]
Signal-to-Noise Ratio (SNR)
V
V
IN
IN
= 6.02 x N + 1.76
MAX4108
MAX4108
100Ω
100Ω
100Ω
100Ω
0.1µF
0.1µF
REFP
REFN
REFP
REFN
1kΩ
1kΩ
1kΩ
1kΩ
R
50Ω
R
50Ω
ISO
ISO
0.1µF
0.1µF
In reality, there are other noise sources besides quanti-
zation noise e.g. thermal noise, reference noise, clock
jitter, etc. SNR is computed by taking the ratio of the
RMS signal to the RMS noise, which includes all spec-
tral components minus the fundamental, the first five
harmonics, and the DC offset.
SINAD is computed by taking the ratio of the RMS sig-
nal to all spectral components minus the fundamental
and the DC offset.
Signal-to-Noise Plus Distortion (SINAD)
C
22pF
C
22pF
IN
IN
22pF
22pF
R
50Ω
C
50Ω
R
C
ISO
IN
ISO
IN
INA+
COM
INA-
INB+
INB-
MAX1182