Circuit Note CN-0204 Devices Connected/Referenced High Voltage Industrial Current/Voltage AD5751 Output Driver with Programmable Ranges Circuits from the Lab reference circuits are engineered and 16-Bit nanoDAC Digital-to-Analog AD5662 tested for quick and easy system integration to help solve todays Converter in SOT-23 analog, mixed-signal, and RF design challenges. For more Ultralow Noise, 4.096V LDO XFET Voltage ADR444 information and/or support, visit www.analog.com/CN0204. Reference with Current Sink and Source Quad-Channel Isolator with Integrated ADuM5401 DC-to-DC Converter ADuM1301 Triple-Channel Digital Isolator Flexible, High Voltage, High Accuracy, Low Drift PLC/DCS Analog Output Module The AD5662 low power (0.75 mW typical 5 V), rail-to-rail EVALUATION AND DESIGN SUPPORT output, 16-bit nanoDAC device and the AD5751 industrial Circuit Evaluation Boards current/voltage output driver are well matched with respect to CN-0204 Circuit Evaluation Board (EVAL-CN0204-SDPZ) input and output voltage ranges, as well as reference voltage System Demonstration Platform (EVAL-SDP-CB1Z) requirements. Design and Integration Files Schematics, Layout Files, Bill of Materials The ADR444, with low drift (3 ppm/ maximum for B grade), high initial accuracy (0.04% maximum for B grade), and low CIRCUIT FUNCTION AND BENEFITS noise (1.8 V p-p typical, 0.1 Hz to 10 Hz), provides the The circuit, shown in Figure 1, provides a full function, high reference voltage for both the AD5751 and AD5662 and voltage (up to 44 V), flexible, programmable analog output guarantees ultralow noise, high accuracy, and low temperature solution that meets most requirements for programmable drift for the circuit. This circuit provides all the typical voltage logic controller (PLC) and distributed control system (DCS) applications. +V ISO +12V TO +55V ADR444 SEE TEXT 4.096V ADuM1301 +5V VOUT VIN 0.1F VDD2 VDD1 0.1F 0.1F GND GND2 GND1 0.1F 10F SCLK VOA VIA SDIN VOB VIB 0V TO 4.096V VIC V V SDO VOC REF DD NC NC SYNC VFB 0.1F 0.1F 0.1F 10F VE1 VE2 SCLK AD5662 VOUT GND1 GND2 DIN GND VREF DVCC AVDD +5V ISO ADuM5401 0V TO 5V VIN VOUT 0V TO 6V 10F SCLK VDD1 VDD2 0.1F 0.1F 10F 0V TO 10V SDIN GND1 GND2 0V TO 12V AD5751 VIA VOA SDO SYNC1 0V TO 40V 0V TO 44V VIB VOB SYNC SYNC2 VIC CLEAR CLR VOC IOUT 4mA TO 20mA VOD FAULT VID GND 0mA TO 20mA FAULT 0mA TO 24mA RCOUT VSEL GND1 GND2 GND ISO Figure 1. Basic Analog Output Circuit for Single Channel (Simplified Schematic, All Connections and Protection Circuits Not Shown) Rev.0 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. suitability and applicability for your use and application. Accordingly, in no event shall Analog Devices Tel: 781.329.4700 www.analog.com 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) Fax: 781.461.3113 2011 Analog Devices, Inc. All rights reserved. 09736-001CN-0204 Circuit Note and current output ranges with 16-bit resolution and no The ADuM1301 is a triple channel digital isolator. The missing codes, 0.05% linearity, and less than 0.2% total output ADuM5401 is a quad channel digital isolator with isoPower error. integrated, isolated, dc-to-dc converter. They are both based on the iCoupler technology. They are used to provide isolation The ADuM1301 and ADuM5401 provide all the necessary between the signal chain and the system microcontroller, with signal isolation between the microcontroller and the analog an isolation rating of 2.5 kV rms. The ADuM5401 provides an signal chain. The ADuM5401 also provides isolated 5 V power. isolated 5 V power supply for all the circuit in the secondary The circuit also contains key features for industrial applications, side. such as on-chip output fault detection, CRC checking to prevent The digital power and analog power should be separated and packet error (PEC), and flexible power-up options, making it an connected with a ferrite bead. Each power is well decoupled by ideal choice for robust industrial control systems. No external a 10 F paralleled with a 0.1 F ceramic capacitor. See the precision resistors or calibration routines are needed to schematics in the CN0204 Design Support package for more maintain consistent performance in mass production, thereby details. making it ideal for PLC or DCS modules. Devices for PLC and DCS applications generally need ESD CIRCUIT DESCRIPTION protection and overvoltage protection much higher than the The AD5751 is a single channel, low cost, precision voltage/ formal recommended specifications. The AD5751 has current output driver developed to meet the requirements of integrated ESD protection diodes internal to each pin that can industrial process control applications. The AD5751 is specified prevent damage from transients. However, the industrial to operate with a power supply range from 10.8 V to 55 V, and control environment can subject I/O circuits to much higher the voltage output can be up to 44 V. The voltage output range transients. External 64 V, 1500 W transient voltage suppressors can be programmed for the standard output ranges and 20% (TVS) a 50 mA, 30 V PolySwitch and power Schottky diodes overrange settings for PLC and DCS applications: 0 V to 5 V, are built into the EVAL-CN0204-SDPZ circuit board to provide 0 V to 10 V, 0 V to 6 V, 0 V to 12 V. In addition, two high voltage higher voltage ESD protection, 50 mA overcurrent, and 64 V output ranges are also provided: 0 V to 40 V and 0 V to 44 V. overvoltage protection. The optional external protection The current output, which is provided on a separate pin, can be circuits are not shown in the simplified schematic of Figure 1 but can be found in the detailed schematic (EVAL-CN0204- programmed for the standard ranges of 4 mA to 20 mA, 0 mA to 20 mA, 0 mA to 24 mA. There is also a 2% overrange setting SDPZ-SCH pdf file) in the CN0204 Design Support package: which provides 3.92 mA to 20.4 mA, 0 mA to 20.4 mA, and www.analog.com/CN0204-DesignSupport. 0 mA to 24.5 mA. The voltage and current output pins can be The circuit must be constructed on a multilayer PC board with tied together to configure the end system as a single-channel a large area ground plane. Proper layout, grounding, and output if desired. decoupling techniques must be used to achieve optimum The AD5662 is a single channel, low cost, low power, rail-to-rail performance (see Tutorial MT-031, Grounding Data Converters voltage buffered output nanoDAC device. The AD5662 and Solving the Mystery ofAGN andDGND and Tutorial guarantees 1 LSB DNL under a wide range of reference MT-101, Decoupling Techniques). voltages that can vary from 0.75 V to the V supply. In the DD Measurements circuit of Figure 1, the AD5751 and AD5662 operate from a Integral nonlinearity (INL), differential nonlinearity (DNL), common reference source of 4.096 V, provided by the ADR444. and output error are the most important specifications for PLC, The whole system will benefit from the ultralow noise and low DCS, and other process control systems. The AD5751 has temperature coefficient of the ADR444. The ADR44x family of highly flexible and configurable output ranges that can be references are ideal for driving either the reference or the power tailored to meet the needs of the application. Measurements of input of converters because they can source and sink current. INL, DNL, and output error for the circuit are shown in Figure 2, The AD5662 also incorporates a power-on reset circuit to Figure 3, and Figure 4, respectively. This data was taken at 25C ensure that the DAC output powers up to either midscale or in the voltage output mode using the internal current sense zero and remains there until a valid write takes place. resistor. The AD5751 range was set for 0 V to 5 V. The test results for all the other ranges are listed in Table 1. Rev. 0 Page 2 of 6