Analog Devices AD5700D2Z Circuit Evaluation Board DEMO-AD5700D2Z DEMO-AD5700D2Z データシート
製品コード
DEMO-AD5700D2Z
Circuit Note
CN-0267
Circuits from the Lab™ reference circuits are engineered and
tested for quick and easy system integration to help solve today’s
analog, mixed-signal, and RF design challenges. For more
information and/or support, visit
tested for quick and easy system integration to help solve today’s
analog, mixed-signal, and RF design challenges. For more
information and/or support, visit
Devices Connected/Referenced
Low Power, Precision Analog
Microcontroller
Microcontroller
16-Bit, Loop Powered, 4 mA to 20 mA
DAC
DAC
Low Power HART Modem
Complete 4 mA to 20 mA Loop Powered Field Instrument with HART Interface
Rev. B
Circuits from the Lab™ circuits from Analog Devices have been designed and built by Analog Devices
engineers. Standard engineering practices have been employed in the design and construction of
each circuit, and their function and performance have been tested and verified in a lab environment at
room temperature. However, you are solely responsible for testing the circuit and determining its
suitability and applicability for your use and application. Accordingly, in no event shall Analog Devices
be liable for direct, indirect, special, incidental, consequential or punitive damages due to any cause
whatsoever connected to the use of any Circuits from the Lab circuits. (Continued on last page)
engineers. Standard engineering practices have been employed in the design and construction of
each circuit, and their function and performance have been tested and verified in a lab environment at
room temperature. However, you are solely responsible for testing the circuit and determining its
suitability and applicability for your use and application. Accordingly, in no event shall Analog Devices
be liable for direct, indirect, special, incidental, consequential or punitive damages due to any cause
whatsoever connected to the use of any Circuits from the Lab circuits. (Continued on last page)
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EVALUATION AND DESIGN SUPPORT
Circuit Evaluation Board
Design and Integration Files
CIRCUIT FUNCTION AND BENEFITS
The circuit shown in Figure 1 is a complete smart industrial,
loop powered field instrument with 4 mA to 20 mA analog output
and a highway addressable remote transducer (HART®) interface.
HART is a digital 2-way communication in which a 1 mA peak-
to-peak frequency-shift-keyed (FSK) signal is modulated on top
of the standard 4 mA to 20 mA analog current signal. This allows
loop powered field instrument with 4 mA to 20 mA analog output
and a highway addressable remote transducer (HART®) interface.
HART is a digital 2-way communication in which a 1 mA peak-
to-peak frequency-shift-keyed (FSK) signal is modulated on top
of the standard 4 mA to 20 mA analog current signal. This allows
features such as remote calibration, fault interrogation, and
transmission of process variables, which are necessary in
applications such as temperature and pressure control.
transmission of process variables, which are necessary in
applications such as temperature and pressure control.
This circuit has been compliance tested, verified, and registered by
the HART Communication Foundation (HCF). This successful
registration provides circuit designers with a high level of
confidence using one or all of the components in the circuit.
the HART Communication Foundation (HCF). This successful
registration provides circuit designers with a high level of
confidence using one or all of the components in the circuit.
The circuit uses the
, an ultralow power, precision
, a 16-bit, 4 mA to 20 mA,
loop powered digital-to-analog converter (DAC), and the
the industry’s lowest power and smallest footprint HART-
compliant IC modem.
compliant IC modem.
Figure 1. 4 mA to 20 mA, Loop Powered Field Instrument with HART Interface (Simplified Schematic: All Connections and Decoupling Not Shown)
50Ω
DAC
LOOP–
C
IN
HART_OUT
ADC_IP
DVDD
COM
AD5421
ADuCM360
REG
IN
PRIMARY
SENSOR
SECONDARY
SENSOR
AD5700
ADC
V
LOOP
TEMPERATURE
SENSOR
REF
IOVDD
XTAL1
CORTEX
M3
+
SRAM
FLASH
+
DMA
UART
SPI
I
2
C
CLOCK
RESET
WATCHDOG
I
EXC
WATCHDOG
TIMER
REG
OUT
20MΩ
1MΩ
4700pF
1.6Ω
10µF
10µF
470Ω
1µF
L*
L*
L*
TVS
40V
LOW
LEAKAGE
4.7V
LOW LEAKAGE
10Ω
10µF
10µF
1.2MΩ
1.2MΩ
300pF
150pF
150kΩ
0.068µF
0.22µF
1µF
SCLK
SDO
SDIN
SYNC
AIN4
AIN0
AIN3
AIN2
0.1µF
0.01µF
0.01µF
0.1µF
AIN7
1kΩ
1kΩ
1kΩ
1kΩ
1kΩ
0.1µF
1kΩ
1kΩ
0.1µF
0.01µF
0.01µF
AIN1
GND_SW
AVDD
AVDD
ADC1
RXD
TXD
CD
RTS
RTS
SCLK0
MISO0
MOSI0
CS0
SIN
P0.5
SOUT
LDAC
XTAL2
V
CC
3.8664MHz
1µF
REG_CAP
AGND
DGND
EXPOSED
PAD
AGND
DGND
AGND
0.47µF
DVDD_
REG
AVDD_
REG
VREF–
VREF+
PT100
VREF
0.47µF
0.1µF
10µF
10µF
DV
DD
REFOUT1
REFOUT2
REFOUT2
P0.4
ADC0
RREF
5.62kΩ
10ppm
SPI INTERFACE
UART INTERFACE
LOOP+
LOOP–
NOTES
1. L* = FERRITE BEAD, 0.3Ω @ DC, 1kΩ @ 100MHz.
2. THE ADuCM360 EXPOSED PAD IS CONNECTED TO DGND.
1. L* = FERRITE BEAD, 0.3Ω @ DC, 1kΩ @ 100MHz.
2. THE ADuCM360 EXPOSED PAD IS CONNECTED TO DGND.
VREF
DVDD
VOLTAGE
REGULATOR
10551-
0
01