MAX1402EVKIT Maxim Integrated Products, MAX1402EVKIT Datasheet - Page 34

• Manufacturer Part Number: MAX1402EVKIT
• Description: EVAL KIT FOR MAX1402
• Manufacturer: Maxim Integrated Products

Specifications of MAX1402EVKIT

• Number Of Adc's: 1
• Number Of Bits: 18
• Sampling Rate (per Second): 480
• Data Interface: Serial
• Inputs Per Adc: 6 Single Ended
• Input Range: ±VREF/2
• Power (typ) @ Conditions: 26.7mW @ 480SPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: 0°C ~ 70°C
• Utilized Ic / Part: MAX1402
• Interface Type: SMA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: MAX1402

+5V, 18-Bit, Low-Power, Multichannel,
Oversampling (Sigma-Delta) ADC
Figure 16. Strain-Gauge Application with MAX1402
Figure 17. Thermocouple Application with MAX1402
34
THERMOCOUPLE
DUMMY
ACTIVE
GAUGE
GAUGE
JUNCTION
______________________________________________________________________________________
+5V
R
REF
ANALOG SUPPLY
R
R
+2.5V
R
R
C
OUT1
OUT2
AIN1
AIN2
CALIBRATION
REFIN+
REFIN-
ADDITIONAL
CHANNELS
ANALOG
AND
C
AIN1
AIN2
REFIN+
REFIN-
AGND
SWITCHING
SWITCHING
NETWORK
NETWORK
MAX1402
DGND
BUFFER
AGND
V+
PGA
BUFFER
BUFFER
BUFFER
BUFFER
MAX1402
Connect the differential inputs of the MAX1402 to the
bridge network of the strain gauge. In Figure 16, the
analog positive supply voltage powers the bridge net-
work and the MAX1402 along with its reference voltage.
The on-chip PGA allows the MAX1402 to handle an
analog input voltage range as low as 20mV full scale.
The differential inputs of the part allow this analog input
range to have an absolute value anywhere between
AGND and V+.
Figure 17 shows a connection from a thermocouple to
the MAX1402. In this application, the MAX1402 is oper-
ated in its buffered mode to allow large decoupling
capacitors on the front end. These decoupling capaci-
tors eliminate any noise pickup form the thermocouple
leads. When the MAX1402 is operated in buffered
mode, it has a reduced common-mode range. In order
to place the differential voltage from the thermocouple
on a suitable common-mode voltage, the AIN2 input of
the MAX1402 is biased at the reference voltage, +2.5V.
AGND
V+
PGA
DGND
DAC
V
DD
MODULATOR
Temperature Measurement
Strain Gauge Operation
DIVIDER
INTERFACE
CONTROL
DIGITAL
FILTER
AND
CLOCK
GEN
CLKIN
CLKOUT
SCLK
DIN
DOUT
INT
CS
RESET
DS1
DS0