MAX1186 Maxim Integrated Products, MAX1186 Datasheet - Page 18

• Manufacturer Part Number: MAX1186
• Description: Low-Power ADC
• Manufacturer: Maxim Integrated Products

Dual 10-Bit, 40Msps, 3V, Low-Power ADC with
Internal Reference and Multiplexed Parallel Outputs
Figure 7: Using an Op Amp for Single-Ended, AC-Coupled Input Drive
tion error only and results directly from the ADC’s reso-
lution (N-Bits):
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.
SINAD is computed by taking the ratio of the RMS sig-
nal to all spectral components minus the fundamental
and the DC offset.
18
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Signal-to-Noise Plus Distortion (SINAD)
SNR
dB[max]
V
V
IN
IN
= 6.02
MAX4108
MAX4108
dB
x N + 1.76
100Ω
100Ω
100Ω
100Ω
dB
0.1µF
0.1µF
REFP
REFN
REFP
REFN
1kΩ
1kΩ
1kΩ
1kΩ
R
50Ω
R
50Ω
ISO
ISO
0.1µF
0.1µF
ENOB specifies the dynamic performance of an ADC at
a specific input frequency and sampling rate. An ideal
ADC error consists of quantization noise only. ENOB is
computed from:
C
22pF
C
22pF
IN
IN
22pF
22pF
50Ω
R
C
50Ω
C
R
ISO
ISO
IN
IN
Effective Number of Bits (ENOB)
ENOB
INA+
COM
INA-
INB+
INB-
MAX1186
=
SINAD
6 02
dB
.
−
dB
1 76
.
dB