MAX1401EAI+ Maxim Integrated Products, MAX1401EAI+ Datasheet - Page 33

• Manufacturer Part Number: MAX1401EAI+
• Description: IC ADC 18BIT LP 28-SSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1401EAI+

• Number Of Bits: 18
• Sampling Rate (per Second): 480
• Data Interface: QSPI™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 750µW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP
• Number Of Adc Inputs: 5
• Architecture: Delta-Sigma
• Conversion Rate: 4.8 KSPs
• Resolution: 18 bit
• Input Type: Voltage
• Interface Type: Serial
• Voltage Reference: External
• Supply Voltage (max): 3 V
• Maximum Power Dissipation: 21.45 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Input Signal Type: Pseudo-Differential, Differential
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Connect the differential inputs of the MAX1401 to the
bridge network of the strain gauge. In Figure 14, the
analog positive supply voltage powers the bridge net-
work and the MAX1401 along with its reference voltage.
The on-chip PGA allows the MAX1401 to handle an
analog input voltage range as low as 10mV full scale.
The differential inputs of the part allow this analog input
range to have an absolute value anywhere between
AGND and V+.
Figure 14. Strain-Gauge Application with MAX1401
DUMMY
ACTIVE
GAUGE
GAUGE
R
REF
ANALOG SUPPLY
R
R
______________________________________________________________________________________
REFIN+
REFIN-
AIN1
AIN2
CALIBRATION
ADDITIONAL
CHANNELS
ANALOG
AND
+3V, 18-Bit, Low-Power, Multichannel,
Strain-Gauge Operation
SWITCHING
NETWORK
Oversampling (Sigma-Delta) ADC
MUXOUT+
MUXOUT-
AGND
V+
ADCIN-
ADCIN+
BUFFER
BUFFER
MAX1401
Figure 15 shows a connection from a thermocouple to
the MAX1401. In this application, the MAX1401 is oper-
ated in its buffered mode to allow large decoupling
capacitors on the front end. These decoupling capaci-
tors eliminate any noise pickup from the thermocouple
leads. When the MAX1401 is operated in buffered mode,
it has a reduced common-mode range. In order to place
the differential voltage from the thermocouple on a suit-
able common-mode voltage, the AIN2 input of the
MAX1401 is biased at the reference voltage, +1.25V.
AGND
V+
PGA
DGND
DAC
V
DD
MODULATOR
Temperature Measurement
DIVIDER
INTERFACE
CONTROL
DIGITAL
FILTER
AND
CLOCK
GEN
CLKIN
CLKOUT
SCLK
DIN
DOUT
INT
CS
RESET
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