Chip information, Ordering information (continued), Typical application circuit – Rainbow Electronics MAX1143 User Manual
Page 18: Effective number of bits, Total harmonic distortion, Spurious-free dynamic range
Effective Number of Bits
Effective number of bits (ENOB) indicates the global
accuracy of an ADC at a specific input frequency and
sampling rate. An ideal ADC’s error consists of quanti-
zation noise only. With an input range equal to the full-
scale range of the ADC, calculate the effective number
of bits as follows:
ENOB = (SINAD - 1.76) / 6.02
Total Harmonic Distortion
Total harmonic distortion (THD) is the ratio of the RMS
sum of the first five harmonics of the input signal 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
Spurious-free dynamic range (SFDR) is the ratio of RMS
amplitude of the fundamental (maximum signal compo-
nent), to the RMS value of the next largest distortion
component.
Chip Information
TRANSISTOR COUNT: 21,807
PROCESS : BiCMOS
THD
=
×
+
+
+
20
2
2
3
2
4
2
5
2
1
log
/
V
V
V
V
V
MAX1142/MAX1143
14-Bit ADC, 200ksps, +5V Single-Supply
with Reference
18
______________________________________________________________________________________
Ordering Information (continued)
PART
TEMP. RANGE
PIN-
PACKAGE
INL
(LSB)
MAX1142AEAP
-40
°
C to +85
°
C
20 SSOP
±
1
MAX1142BEAP
-40
°
C to +85
°
C
20 SSOP
±
2
MAX1143
ACAP*
0
°
C to +70
°
C
20 SSOP
±
1
MAX1143BCAP*
0
°
C to +70
°
C
20 SSOP
±
2
MAX1143AEAP*
-40
°
C to +85
°
C
20 SSOP
±
1
MAX1143BEAP*
-40
°
C to +85
°
C
20 SSOP
±
2
AV
DD
DV
DD
SCLK
SCLK
MOSI
MISO
I/O
I/O
DIN
DOUT
SSTRB
DGND AGND
REFADJ
REF
AIN
TO DGND
MC68HCXX
0.1
µ
F
0.22
µ
F
2.2
µ
F
RST
CS
SHDN
MAX1142
MAX1143
0.1
µ
F
+5V
+5V
1
µ
F
CREF
Typical Application Circuit
*Future product—contact factory for availability.