Rainbow Electronics MAX1444 - Manual (Page 16)

MAX1444
10-Bit, 40Msps, +3.0V, Low-Power
ADC with Internal Reference
16 ______________________________________________________________________________________
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
ADC’s error consists of quantization noise only. ENOB
is computed from:
ENOB = (SINAD - 1.76dB) / 6.02dB
Total Harmonic Distortion (THD)
THD is typically the ratio of the RMS sum of the input
signal’s first five harmonics to the fundamental itself.
This is expressed as:
where V 1 is the fundamental amplitude, and V 2 through
V
5
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 at -6.5dB full scale, and their envelope is at -0.5dB
full scale.
___________________Chip Information
TRANSISTOR COUNT: 5684
PROCESS: CMOS
HOLD
ANALOG
INPUT
SAMPLED
DATA (T/H)
T/H
t
AD
t AJ
TRACK TRACK
CLK
Figure 10. T/H Aperture Timing
THD V V V V V = × + + +
( )
20
2
2
3
2
4
2
5
2
1
log /