MAX1185_10 Datasheet, PDF (18/21 Pages) Maxim Integrated Products – Dual 10-Bit, 20Msps, 3V, Low-Power ADC with Internal Reference and Multiplexed Parallel Outputs

Dual 10-Bit, 20Msps, 3V, Low-Power ADC with
Internal Reference and Multiplexed Parallel Outputs
DOWNCONVERTER
Figure 8. Typical QAM Application, Using the MAX1185
CLK
ANALOG
INPUT
t_AD
SAMPLED
DATA (T/H)
T/H ^TRACK
t_AJ
HOLD
TRACK
Figure 9. T/H Aperture Timing
MAX2451
0°
90°
÷₈
INA+
A/B
INA-
MAX1185
INB+
INB-
DSP
POST
PROCESSING
CHA AND CHB DATA
ALTERNATINGLY
AVAILABLE ON 10-BIT,
MULTIPLEXED
OUTPUT BUS
Total Harmonic Distortion (THD)
THD is typically the ratio of the RMS sum of the first four
harmonics of the input signal to the fundamental itself.
This is expressed as:
⎛
THD
=
20
× log₁₀
⎜
⎜
⎝
V₂ ²
+
V₃ ²
+ V₄₂
+ V₅₂
⎞
⎟
V₁
⎟
⎠
where V₁ is the fundamental amplitude, and V₂ through
V₅ are the amplitudes of the 2nd- through 5th-order
harmonics.
Spurious-Free Dynamic Range (SFDR)
SFDR is the ratio expressed in decibels of the RMS
amplitude of the fundamental (maximum signal compo-
nent) to the RMS value of the next largest spurious
component, excluding DC offset.
Intermodulation Distortion (IMD)
The two-tone IMD is the ratio expressed in decibels of
either input tone to the worst 3rd-order (or higher) inter-
modulation products. The individual input tone levels
are backed off by 6.5dB from full scale.
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