EVAL-AD7714-3EB Analog Devices Inc, EVAL-AD7714-3EB Datasheet - Page 38

• Manufacturer Part Number: EVAL-AD7714-3EB
• Description: BOARD EVAL FOR AD7714-3
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7714-3EB

• Rohs Status: RoHS non-compliant
• Number Of Adc's: 1
• Number Of Bits: 24
• Sampling Rate (per Second): 1k
• Data Interface: Serial
• Inputs Per Adc: 3 Differential
• Input Range: 0 ~ 3.3 V
• Power (typ) @ Conditions: 3.65mW @ 3.3 V
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7714-3

AD7714
Smart Transmitters
Another area where the low power, single supply, three-wire
interface capabilities is of benefit is in smart transmitters. Here,
the entire smart transmitter must operate from the 4 mA to
20 mA loop. Tolerances in the loop mean that the amount of
current available to power the transmitter is as low as 3.5 mA.
AMBIENT
SENSOR
TEMP.
SENSORS
ohm
RTD
mV
TC
DV
DD
AD7714
AV
DGND
DD
ISOLATED GROUND
ISOLATED SUPPLY
AGND
REF IN
MCLK
IN
MCLK
OUT
REFERENCE
VOLTAGE
Figure 16. Smart Transmitter Using the AD7714
ISOLATION
BARRIER
MICROCONTROLLER UNIT
*PID
*RANGE SETTING
*CALIBRATION
*LINEARIZATION
*OUTPUT CONTROL
*SERIAL COMMUNICATION
*HART PROTOCOL
–38–
MAIN TRANSMITTER ASSEMBLY
V
The AD7714 consumes only 500 A, leaving 3 mA available for
the rest of the transmitter. Figure 16 shows a block diagram of a
smart transmitter which includes the AD7714. Not shown in
Figure 16 is the isolated power source required to power the
front end.
COM
CC
COM
3V
CONVERTER
BELL 202
MODEM
HART
REFERENCE
D/A
VOLTAGE
WAVEFORM
SHAPER
CONDITIONER
3V
SIGNAL
REGULATOR
INPUT/OUTPUT
VOLTAGE
STAGE
BANDPASS
FILTER
LOOP
RTN
4–20mA
REV. C