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MAX1185 Datasheet, PDF (17/20 Pages) Maxim Integrated Products – Dual 10-Bit, 20Msps, +3V, Low-Power ADC with Internal Reference and Multiplexed Parallel Outputs | |||
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Dual 10-Bit, 20Msps, +3V, Low-Power ADC with
Internal Reference and Multiplexed Parallel Outputs
REFP
VIN
0.1µF
1k⦠RISO
50â¦
MAX4108
100â¦
INA+
CIN
1kâ¦
22pF
100â¦
COM
REFN
0.1µF
RISO
50â¦
INA-
CIN
22pF
REFP
MAX1185
VIN
0.1µF
1k⦠RISO
50â¦
MAX4108
100â¦
INB+
CIN
1kâ¦
22pF
100â¦
REFN
0.1µF
RISO
50â¦
INB-
CIN
22pF
Figure 7: Using an Op Amp for Single-Ended, AC-Coupled Input Drive
quantization error (residual error). The ideal, theoretical
minimum analog-to-digital noise is caused by quantiza-
tion error only and results directly from the ADCâs reso-
lution (N-Bits):
SNRdB[max] = 6.02dB x N + 1.76dB
In reality, there are other noise sources besides quanti-
zation noise: 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 spectral
components minus the fundamental, the first five har-
monics, and the DC offset.
Signal-to-Noise Plus Distortion (SINAD)
SINAD is computed by taking the ratio of the RMS sig-
nal to all spectral components minus the fundamental
and the DC offset.
Effective Number of Bits (ENOB)
ENOB specifies the dynamic performance of an ADC at
a specific input frequency and sampling rate. An ideal
ADCs error consists of quantization noise only. ENOB is
computed from:
ENOB = SINADdB â 1.76dB
6.02dB
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