MAX1281BEUP-T Maxim Integrated, MAX1281BEUP-T Datasheet - Page 22

• Manufacturer Part Number: MAX1281BEUP-T
• Description: Analog to Digital Converters - ADC
• Manufacturer: Maxim Integrated

Specifications of MAX1281BEUP-T

• Number Of Channels: 8/4
• Architecture: SAR
• Conversion Rate: 300 KSPs
• Resolution: 12 bit
• Input Type: Single-Ended/Pseudo-Differential
• Snr: 70 dB
• Interface Type: 4-Wire (SPI, Microwire, QSPI, TMS320)
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-20
• Maximum Power Dissipation: 559 mW
• Minimum Operating Temperature: - 40 C
• Number Of Converters: 1
• Voltage Reference: 2.5 V

Serial 12-Bit ADCs with Internal Reference
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.
Figure 19. MAX1280/MAX1281-to-TMS320 Serial Interface
22
400ksps/300ksps, Single-Supply, Low-Power, 8-Channel,
SSTRB
DOUT
SCLK
DIN
______________________________________________________________________________________
CS
THD
1
=
is the fundamental amplitude, and V
20
START
ENOB = (SINAD - 1.76) / 6.02
Total Harmonic Distortion (THD)
×
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
+
V
2
5
through
PD1
2
⎞
⎟
⎠
PD0
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.
ANALOG
INPUTS
0.01µF
+2.5V
4.7µF
0 TO
MSB
Typical Operating Circuit
CH0
CH8
REF
REFADJ
MAX1280
MAX1281
Spurious-Free Dynamic Range
B10
SSTRB
DOUT
SHDN
SCLK
V
V
COM
GND
DD1
DD2
DIN
CS
B1
B0
+5V OR
+3V
0.1µF
I/O
SCK (SK)
MISO (SI)
V
MOSI (SO)
DD
HIGH IMPEDANCE
HIGH IMPEDANCE
CPU
V
SS