Circuit Note CN-0203 Devices Connected/Referenced 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 www.analog.com/CN0203. AD5750-1 AD5660-1 Industrial Current/Voltage Output Driver with Programmable Ranges 16-Bit nanoDAC® Digital-to-Analog Converter with 5 ppm/°C On-Chip Reference in SOT-23 Flexible PLC/DCS Analog Output Module Using Only Two Analog Components applications. The AD5660-1 low power (2.8 mW @ 5 V), rail-torail output, 16-bit nanoDAC®, combined with the AD5750-1 industrial current/voltage output driver, provides all the typical current and voltage output ranges with 16-bit resolution and no missing codes, 0.05% linearity, and less than 0.1% output error. The circuit also contains key features for industrial applications, such as on-chip output fault detection, CRC checking to prevent packet error (PEC), and flexible power-up options, making it an ideal choice for robust industrial control systems. No external precision resistors or calibration routines are needed to maintain consistent performance in mass production, thereby making it ideal for PLC or DCS modules. EVALUATION AND DESIGN SUPPORT Circuit Evaluation Boards CN-0203 Circuit Evaluation Board (EVAL-CN0203-SDPZ) 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 provides a full function, flexible, programmable analog output solution with only two analog components and meets most requirements for programmable logic controller (PLC) and distributed control system (DCS) +15V 10µF + 0.1µF +1.25V 0.1µF +5V 10µF VREFOUT SYNCA SYNC SCLK SCLK SDIN SDIN 0.1µF VDD AD5660-1 GND + VFB VOUT 0V TO +2.5V SYNCB DVCC VREF AVDD VIN VOUT SYNC SCLK SCLK SDIN SDIN SDO SDO AD5750-1 IOUT GND AVSS 0V TO 5V 0V TO 10V ±5V, ±10V 4mA TO 20mA 0mA TO 20mA 0mA TO 24mA ±20mA, ±24mA 10µF + 0.1µF 09735-001 –15V Figure 1. Basic Analog Output Circuit for Single Channel (Simplified Schematic, All Connections and Protection Circuits Not Shown) Rev.A 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) One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2011 Analog Devices, Inc. All rights reserved. CN-0203 Circuit Note 5 4 3 2 0 –1 –2 –3 The interface between the AD5660-1 DAC and the AD5750-1 driver is simple and requires no external components. The output voltage range of the AD5660-1 is 0 V to 2.5 V, which matches the input range of the AD5750-1. In addition, the reference output voltage of the AD5660-1 is 1.25 V, which precisely matches the reference input requirement of the AD5750-1. 09735-002 –4 53248 57344 61440 65536 53248 57344 61440 65536 49152 45056 40960 36864 32768 28672 24576 20480 16384 8192 12288 0 –5 DAC CODE Figure 2. INL for 0 V to 5 V Output Range 0.8 0.6 0.4 The circuit must be constructed on a multilayer PC board with a large area ground plane. Proper layout, grounding, and decoupling techniques must be used to achieve optimum performance (see Tutorial MT-031, Grounding Data Converters Rev. A | Page 2 of 6 0.2 0 –0.2 –0.4 09735-003 –0.6 49152 45056 40960 36864 32768 28672 24576 20480 16384 12288 –0.8 8192 DNL (LSB) Devices for PLC and DCS applications generally need ESD protection and overvoltage protection much higher than the formal recommend specifications. The AD5750-1 has integrated ESD protection diodes internal to each pin that can prevent damage from a 3 kV transient (Human Body Model). However, the industrial control environment can subject I/O circuits to much higher transients. External 30 V, 600 W transient voltage suppressors (TVS), a 50 mA, 30 V PolySwitch, and power Schottky diodes are built into the EVAL-CN0203-SDPZ circuit board to provide higher voltage ESD protection, 50 mA overcurrent, and 30 V overvoltage protection. The optional external protection circuits are not shown in the simplified schematic of Figure 1 but can be found in the detailed schematic (EVAL-CN0203-SDPZ-SCH pdf file) in the CN0203 Design Support package: www.analog.com/CN0203-DesignSupport. 1 4096 The AD5660-1 is a single channel, low cost, low power, rail-torail voltage buffered output nanoDAC integrated with an onchip 1.25 V, 5 ppm/°C reference. The AD5660-1incorporates a power-on reset circuit to ensure that the DAC output powers up to 0 V and remains there until a valid write command takes place. Integral nonlinearity (INL), differential nonlinearity (DNL), and output error are the most important specifications for PLC, DCS, and other process control systems. The AD5750-1 has highly flexible and configurable output ranges that can be tailored to meet the needs of the application. Measurements of INL, DNL, and output error for the circuit are shown in Figure 2, Figure 3, and Figure 4, respectively. This data was taken at 25°C in the voltage output mode using the internal current sense resistor. The AD5750-1 range was set for 0 V to 5 V. The test results for all the other ranges are listed in Table 1. 4096 The current output, which is provided on a separate pin, can be programmed for the ranges of 4 mA to 20 mA, 0 mA to 20 mA, −20 mA to +20 mA, 0 mA to 24 mA, and −24 mA to +24 mA. The unipolar ranges have a 2% overrange setting. Because the AD5750/AD5750-1 current output can either source or sink current, it can interface to a wide variety of sensors or actuators. The voltage and current output pins can be tied together to configure the end system as a single-channel output if desired. Measurements 0 The AD5750/AD5750-1 are single-channel, low cost, precision voltage/current output drivers developed to meet the requirements of industrial process control applications. The voltage output range can be programmed for the standard output ranges for PLC and DCS applications: 0 V to 5 V, 0 V to 10 V, −5 V to +5 V, and −10 V to +10 V. A 20% overrange setting is also provided for the standard ranges, giving the following options: 0 V to 6 V, 0 V to 12 V, −6 V to +6 V, and −12 V to +12 V. and Solving the Mystery of "AGND" and "DGND," and Tutorial MT-101, Decoupling Techniques). INL (LSB) CIRCUIT DESCRIPTION DAC CODE Figure 3. DNL for 0 V to 5 V Output Range Circuit Note CN-0203 0.060 The test results shown in Table 1 were made at 25°C using the EVAL-CN0203-SDPZ board powered by an Agilent E3631A dc supply and measured with an Agilent 34401A digital multimeter. OUTPUT ERROR (%FSR) 0.055 0.050 Note that the output ranges 0 mA to 20.4 mA and 0 mA to 24.5 mA are both designed to be trimmed by the customer to precisely match the 0 mA to 20 mA and 0 mA to 24 mA ranges. The 0.24% FSR output error measurement in the 0 mA to +24.5 mA range includes the gain error, which is removed by customer calibration. 0.045 0.040 61440 57344 53248 49152 45056 40960 36864 32768 28672 24576 20480 16384 8192 12288 0 4096 0.030 65536 09735-004 0.035 DAC CODE Figure 4. Output Error for 0 V to 5 V Output Range Table 1. Test Results for All Output Ranges Range Current Sense Resistor INL (LSB) Linearity (%FSR) Ouptut Error (%FSR) 0 V to 5 V Don't care 7.1 0.011 0.05 0 V to 10 V Don't care 6.1 0.009 0.05 −5 V to +5 V Don't care 6.2 0.009 0.04 −10 V to +10 V Don't care 6.8 0.010 0.04 0 V to 6 V Don't care 6.9 0.010 0.05 0 V to 12 V Don't care 5.3 0.008 0.09 −6 V to +6 V Don't care 8.0 0.012 0.06 −12 V to +12 V Don't care 7.4 0.011 0.08 −2.5 V to +2.5 V Don't care 5.6 0.008 0.05 4 mA to 20 mA Internal 6.3 0.010 0.07 4 mA to 20 mA External 6.2 0.010 0.07 0 mA to 20 mA Internal 5.8 0.009 0.06 0 mA to 20 mA External 5.7 0.009 0.06 0 mA to 24 mA Internal 5.4 0.008 0.07 0 mA to 24 mA External 5.5 0.008 0.06 −20 mA to +20 mA Internal 8.8 0.013 0.05 −20 mA to +20 mA External 9.3 0.014 0.05 −24 mA to +24 mA Internal 9.2 0.014 0.05 −24 mA to +24 mA External 10.1 0.015 0.04 3.92 mA to +20.4 mA Internal 6.7 0.010 0.03 0 mA to +20.4 mA Internal 7.6 0.012 0.05 0 mA to +24.5 mA Internal 3.4 0.007 0.24 Rev. A | Page 3 of 6 CN-0203 Circuit Note COMMON VARIATIONS Getting Started Load the evaluation software by placing the CN-0203 Evaluation Software disc in the CD drive of the PC. Using "My Computer," locate the drive that contains the evaluation software disc and open the Readme file. Follow the instructions contained in the Readme file for installing and using the evaluation software. The AD5620 (12-bit) and AD5640 (14-bit) are pin-compatible with the AD5660 for applications not requiring 16-bit resolution. For multichannel applications, the AD5623R (12-bit), AD5643R (14-bit), and AD5663R (16-bit) are dual nanoDAC devices, and the AD5624R (12-bit), AD5644R (14-bit), and AD5664R (16-bit) are quad nanoDAC devices. Functional Block Diagram Figure 5 shows a functional block diagram of the test setup. The pdf file “EVAL-CN0203-SDPZ-SCH” contains the detailed circuit schematics for the CN-0203 evaluation board. This file is contained in the CN-0203 Design Support Package: www.analog.com/CN0203-DesignSupport. The AD5750 driver is pin-compatible with the AD5750-1 and can accept a 0 V to 4.096 V input range when used with a 4.096 V reference. The AD5751 is a unipolar analog output driver and can supply a 40 V output using a 50 V AVDD supply. CIRCUIT EVALUATION AND TEST Setup Connect the 120-pin connector on the EVAL-CN0203-SDPZ circuit board to the connector marked “CON A” or “CON B” on the EVAL-SDP-CB1Z evaluation (SDP) board. Nylon hardware should be used to firmly secure the two boards, using the holes provided at the ends of the 120-pin connectors. After successfully setting the dc output supply to +15 V, −15 V and +6 V output, turn the power supply off. Equipment Needed (Equivalents Can Be Substituted) • System Demonstration Platform (EVAL-SDP-CB1Z) • CN-0203 Circuit Evaluation Board (EVAL-CN0203-SDPZ) • CN-0203 Evaluation Software • Software for controlling external test measurement equipment (not included on CD) • Agilent 34401A 6.5 Digital Multimeter With power to the supply off, connect a +15 V power supply to pin of CN1 marked “+15 V,” a −15 V power supply to the pin of CN1 marked “−15 V” and “GND” to the pin of CN1 marked “GND”. Connect +6 V to CN2 the same way. Turn on the power supply and then connect USB cable with the SDP board to the USB port on the PC. Note: Do not connect the USB cable to the mini USB connector on the SDP board before turning on the dc power supply for the EVAL-CN0203-SDPZ. • PC (Windows® 2000 or Windows XP) with USB interface • National Instruments GPIB to USB-B interface and cable AGILENT E3631A TRIPLE POWER SUPPLY GND +6V CN2 EVAL-CN0203-SDPZ VOUT OR IOUT 120 PIN SDP CN3 OR CN4 GND CN1 GPIB OUT +15V −15V GND AGILENT 34401A MULTIMETER Figure 5. Test Setup Functional Block Diagram Rev. A | Page 4 of 6 USB PC USB USB SDP CON A OR CON B 09735-005 • Agilent E3631A 0 V to 6 V/5 A; ±25 V/1 A Triple Output DC Power Supply Circuit Note CN-0203 Table 2. Jumper Settings for EVAL-CN0203-SDPZ (Bolded Values Are Default Settings) Jumper Descriptions Setting Function Shorting Pin1 with Pin2 Address of AD5750 : b'001 Shorting Pin3 with Pin2 Address of AD5750 : b'000 JP1 Sets the address of AD5750-1 Shorting Adding 1 nF Compensation Capacitor JP2 Sets the external compensation capacitor Opening Removing 1 nF Compensation Capacitor Shorting Shorting VSENSE+ with VOUT internally JP3 VSENSE+ Setting Opening VSENSE+ has no connection with VOUT internally Shorting Shorting VSENSE− with GND internally Opening VSENSE− has no connection with GND internally Shorting Shorts VOUT and IOUT together. Opening VOUT and IOUT have no connection internally Shorting Clears to midscale Opening Clears to zero scale JP4 VSENSE− Setting JP5 Shorts the VOUT and IOUT pins JP6 Sets the CLEAR Mode for AD5750-1 Test LEARN MORE After setting up the test equipment, connect the pin of CN3 marked “VOUT” or the pin of CN4 marked “IOUT” to the input of the Agilent 34401A. Make sure that the cable connection on the front panel of the Agilent 34401A is correct, depending on the different input signal type (current or voltage). Testing the INL, DNL, and total error will take a considerable amount of time because all of the AD5660-1 16-bit DAC levels must be set and measured by the 34401A. CN-0203 Design Support Package: www.analog.com/CN0203-DesignSupport The software provided on the CD allows the DAC codes to be set by the PC. An automatic test program is necessary to step through the codes and analyze the data. This is not provided on the CD but must be implemented by the customer to correspond to the requirements of the particular multimeter used in the test setup. In the test configuration shown in Figure 5, the GPIB output of the 34401A multimeter interfaces to a second USB port on the PC using the National Instruments GPIB to USB-B interface and cable. This allows the multimeter readings corresponding to each code to be loaded into an Excel spreadsheet in the PC. The data is then be analyzed for INL, DNL, and total error using industry-standard definitions. For more details on the definitions and how to calculate the INL, DNL, and total error from the measured data, see the "TERMINOLOGY" section of the AD5662 data sheet and also the following reference: Data Conversion Handbook, "Testing Data Converters," Chapter 5, Analog Devices. Slattery, Colm, Derrick Hartmann, and Li Ke, "PLC Evaluation Board Simplifies Design of Industrial Process Control Systems.” Analog Dialogue (April 2009). CN-0063 Circuit Note, 16-Bit Fully Isolated Voltage Output Module Using the AD5662 DAC, ADuM1401 Digital Isolator, and External Amplifiers, Analog Devices. CN-0064 Circuit Note, 16-Bit Fully Isolated 4 mA to 20 mA Output Module Using the AD5662 DAC, ADuM1401 Digital Isolator, and External Amplifiers, Analog Devices. CN-0065 Circuit Note, 16-Bit Fully Isolated Output Module Using the AD5422 Single Chip Voltage and Current Output DAC and the ADuM1401 Digital Isolator, Analog Devices. CN-0066 Circuit Note, Fully Isolated Input Module Based on the AD7793 24-Bit Σ-Δ ADC and the ADuM5401 Digital Isolator, Analog Devices. CN-0067 Circuit Note, Fully Isolated Input Module Based on the AD7793 24-Bit Σ-Δ ADC, the ADuM5401 Digital Isolator, and a High Performance In-Amp, Analog Devices. CN-0097 Circuit Note, Simplified 12-Bit Voltage and 4 mA-to-20 mA Output Solution Using the AD5412, Analog Devices. CN-0209 Circuit Note, Fully Programmable Universal Analog Front End for Process Control Applications, Analog Devices. MT-031 Tutorial, Grounding Data Converters and Solving the Mystery of “AGND” and “DGND”, Analog Devices. Rev. A | Page 5 of 6 CN-0203 Circuit Note MT-101 Tutorial, Decoupling Techniques, Analog Devices. REVISION HISTORY Kester, Walt. Practical Design Techniques for Sensor Signal Conditioning, Analog Devices, 1999, ISBN 0-916550-20-6 11/11—Rev. 0 to Rev. A Kester, Walt. Data Conversion Handbook, Chapter 5, Analog Devices. Change to Table 1 ..............................................................................3 9/11—Revision 0: Initial Version Data Sheets and Evaluation Boards CN-0203 Circuit Evaluation Board (EVAL-CN0203-SDPZ) System Demonstration Platform (EVAL-SDP-CB1Z) AD5750-1 Data Sheet AD5750-1 Evaluation Board AD5660-1 Data Sheet AD5660-1 Evaluation Board AD5662 Data Sheet (Continued from first page) Circuits from the Lab circuits are intended only for use with Analog Devices products and are the intellectual property of Analog Devices or its licensors. While you may use the Circuits from the Lab circuits in the design of your product, no other license is granted by implication or otherwise under any patents or other intellectual property by application or use of the Circuits from the Lab circuits. Information furnished by Analog Devices is believed to be accurate and reliable. However, "Circuits from the Lab" are supplied "as is" and without warranties of any kind, express, implied, or statutory including, but not limited to, any implied warranty of merchantability, noninfringement or fitness for a particular purpose and no responsibility is assumed by Analog Devices for their use, nor for any infringements of patents or other rights of third parties that may result from their use. Analog Devices reserves the right to change any Circuits from the Lab circuits at any time without notice but is under no obligation to do so. ©2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. CN09735-0-11/11(A) Rev. A | Page 6 of 6