MAX1421 Maxim, MAX1421 Datasheet - Page 14

• Manufacturer Part Number: MAX1421
• Description: 12-Bit / 40Msps / +3.3V / Low-Power ADC with Internal Reference
• Manufacturer: Maxim

error specification of less than 1LSB guarantees no
missing codes.
Figure 10 depicts the aperture jitter (t
sample-to-sample variation in the aperture delay.
Aperture delay (t
falling edge of the sampling clock and the instant when
an actual sample is taken (Figure 10).
For a waveform perfectly reconstructed from digital
samples, the theoretical maximum SNR is the ratio of
12-Bit, 40Msps, +3.3V, Low-Power ADC
with Internal Reference
14
Figure 7. Typical Application Circuit for Single-Ended to Differential Conversion
INPUT
______________________________________________________________________________________
300Ω
MAX4108
Dynamic Parameter Definitions
+5V
-5V
300Ω
AD
) is the time defined between the
0.1µF
0.1µF
Signal-to-Noise Ratio (SNR)
300Ω
300Ω
300Ω
300Ω
AJ
Aperture Delay
600Ω
Aperture Jitter
600Ω
), which is the
0.1µF
0.1µF
MAX4108
MAX4108
-5V
+5V
+5V
-5V
600Ω
300Ω
0.1µF
0.1µF
0.1µF
0.1µF
the full-scale analog input (RMS value) to the RMS
quantization error (residual error). The ideal theoretical
minimum analog-to-digital noise is caused by quantiza-
tion error only and results directly from the ADCs reso-
lution (N-bits):
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 four
harmonics, and the DC offset.
0.1µF
0.22µF
SNR
*TWO C
ONE 44pF CAP, TO IMPROVE PERFORMANCE.
LOWPASS FILTER
LOWPASS FILTER
R
50Ω
50Ω
R
ISO
(MAX)
ISO
IN
(22pF) CAPS MAY BE REPLACED BY
= (6.02
44pF*
C
22pF
1nF
C
22pF
IN
IN
*
*
✕
N + 1.76)dB
INP
CML
INN
MAX1421