CN0336 Datasheet, PDF (1/7 Pages) Analog Devices – Devices Connected

Circuits from the Lab® reference designs 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 www.analog.com/CN0336.
Circuit Note
CN-0336
Devices Connected/Referenced
AD8606
Precision, Low Noise, CMOS, Rail-to-Rail
Input/Output Op Amp
AD7091R
1 MSPS, Ultralow Power, 12-Bit ADC
ADuM5401
4-Channel, 2.5 kV Isolators with
Integrated DC-to-DC Converter
12-Bit, 300 kSPS, Single-Supply, Fully Isolated, Data Acquisition System for 4-20 mA
Inputs
EVALUATION AND DESIGN SUPPORT
Circuit Evaluation Boards
CN0336 Circuit Evaluation Board (EVAL-CN0336-PMDZ)
SDP/PMD Interposer Board (SDP-PMD-IB1Z)
System Demonstration Platform (EVAL-SDP-CB1Z)
Design and Integration Files
Schematics, Layout Files, Bill of Materials
CIRCUIT FUNCTION AND BENEFITS
The circuit shown in Figure 1 is a completely isolated 12-bit,
300 kSPS data acquisition system utilizing only three active devices.
The system processes 4 mA to 20 mA input signals using a single
3.3 V supply. The total error after room temperature calibration
is ±0.06% FSR over a ±10°C temperature change, making it ideal
for a wide variety of industrial measurements
The small footprint of the circuit makes this combination an
industry-leading solution for 4 mA to 20 mA data acquisition
systems where the accuracy, speed, cost, and size play a critical
role. Both data and power are isolated, thereby making the
circuit robust to high voltages and also ground-loop interference
often encountered in harsh industrial environments.
VREF
2.5V
U1B
1/2 AD8606
+3.3V
J2
D1
I_IN 1N4148
R1
R4
5.11kΩ
TP1
U1A ^{0.1V TO 2.4V}
1/2 AD8606
INPUT
C10
4mA TO 20mA
R3
120Ω
GND_ISO
GND_ISO
GND_ISO
R5
R6 1kΩ
124kΩ
R2
V_IN
C11
51Ω _4.7nF
GND_ISO
GND_ISO
U2
ADuM5401
(C-GRADE)
+3.3V
+3.3V
V_ISO
V_DD1
GND_ISO GND1
REF_OUT V_DD
CS
V_OA
V_IA
U3
AD7091R
SCLK
CONVST
V_OB
V_IB
V_OC
V_IC
SDO
V_ID
V_OD
GND REGCAP VDRIVE ^+3.3V
V_SEL
RC_OUT
C8
GND_ISO GND1
1µF
GND_ISO
GND_ISO
+3.3V_IN
GND
SS
SCK
CONVST
MISO
GND
PMOD CON
12-PIN
J1
Figure 1. 4 mA to 20 mA Single Supply Analog to Digital Conversion with Isolation (All Connections and Decoupling Not Shown)
Rev. A
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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
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to any cause whatsoever connected to the use of any Circuits from the Lab circuits. (Continued on last page)
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