MAX1280 Maxim, MAX1280 Datasheet - Page 22

• Manufacturer Part Number: MAX1280
• Description: MAX1280 Evaluation System
• Manufacturer: Maxim

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:
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
V5 are the amplitudes of the 2nd- through 5th-order har-
monics, respectively.
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.
Serial 12-Bit ADCs with Internal Reference
Figure 19. MAX1280/MAX1281-to-TMS320 Serial Interface
22
400ksps/300ksps, Single-Supply, Low-Power, 8-Channel,
SSTRB
DOUT
SCLK
DIN
THD
______________________________________________________________________________________
CS
1
=
is the fundamental amplitude, and V
20
START
ENOB = (SINAD - 1.76) / 6.02
Total Harmonic Distortion (THD)
×
Spurious-Free Dynamic Range
log
SEL2



Effective Number of Bits
V
SEL1
2
2
+
V
3
SEL0
2
+
V
V
UNI/BIP SGI/DIF
4
1
2
+
V
4
2
+
2
V
5
through
PD1
2



PD0
TRANSISTOR COUNT: 4286
PROCESS: BiCMOS
___________________Chip Information
MAX1281BCUP
MAX1281BEUP
Ordering Information (continued)
ANALOG
INPUTS
PART
0.01µF
+2.5V
4.7µF
0 TO
MSB
Typical Operating Circuit
CH0
CH8
REF
REFADJ
MAX1280
MAX1281
-40°C to +85°C
0°C to +70°C
B10
RANGE
TEMP.
SSTRB
SHDN
DOUT
SCLK
V
COM
V
GND
DD1
DD2
DIN
CS
B1
B0
+5V OR
+3V
0.1µF
20 TSSOP
20 TSSOP
PACKAGE
PIN-
V
I/O
SCK (SK)
MOSI (SO)
MISO (SI)
DD
HIGH IMPEDANCE
HIGH IMPEDANCE
CPU
V
SS
(LSB)
±1
±1
INL