MAX1280 Datasheet, PDF (22/24 Pages) Maxim Integrated Products – 400ksps/300ksps, Single-Supply, Low-Power, 8-Channel, Serial 12-Bit ADCs with Internal Reference

400ksps/300ksps, Single-Supply, Low-Power, 8-Channel,
Serial 12-Bit ADCs with Internal Reference
CS
SCLK
DIN
SSTRB
DOUT
START SEL2 SEL1 SEL0 UNI/BIP SGI/DIF PD1 PD0
Figure 19. MAX1280/MAX1281-to-TMS320 Serial Interface
MSB B10 B1 B0
HIGH IMPEDANCE
HIGH IMPEDANCE
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 (THD)
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:
THD = 20 ×

log ^
V₂₂
+
V₃₂
+
V₄₂
+
V₄₂
+
V₅₂


V₁
where V₁ is the fundamental amplitude, and V₂ through
V5 are the amplitudes of the 2nd- through 5th-order har-
monics, respectively.
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.
Ordering Information (continued)
PART
TEMP.
RANGE
MAX1281BCUP 0°C to +70°C
MAX1281BEUP -40°C to +85°C
PIN-
PACKAGE
20 TSSOP
20 TSSOP
INL
(LSB)
±1
±1
Typical Operating Circuit
0 TO
+2.5V
ANALOG
INPUTS
4.7µF
0.01µF
CH0
V_DD1
V_DD2
MAX1280 _GND
MAX1281
CH8
COM
REF
CS
SCLK
DIN
REFADJ DOUT
SSTRB
SHDN
+5V OR
+3V
V_DD
0.1µF
CPU
I/O
SCK (SK)
MOSI (SO)
MISO (SI)
V_SS
___________________Chip Information
TRANSISTOR COUNT: 4286
PROCESS: BiCMOS
22 ______________________________________________________________________________________