Circuit Note CN-0203 Devices Connected/Referenced Circuits from the Lab reference circuits are engineered and Industrial Current/Voltage Output Driver tested for quick and easy system integration to help solve todays AD5750-1 with Programmable Ranges analog, mixed-signal, and RF design challenges. For more 16-Bit nanoDAC Digital-to-Analog Converter information and/or support, visit www.analog.com/CN0203. AD5660-1 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-to- EVALUATION AND DESIGN SUPPORT rail output, 16-bit nanoDAC, combined with the AD5750-1 Circuit Evaluation Boards industrial current/voltage output driver, provides all the typical CN-0203 Circuit Evaluation Board (EVAL-CN0203-SDPZ) current and voltage output ranges with 16-bit resolution and no System Demonstration Platform (EVAL-SDP-CB1Z) missing codes, 0.05% linearity, and less than 0.1% output error. Design and Integration Files The circuit also contains key features for industrial applications, Schematics, Layout Files, Bill of Materials such as on-chip output fault detection, CRC checking to prevent CIRCUIT FUNCTION AND BENEFITS packet error (PEC), and flexible power-up options, making it an The circuit shown in Figure 1 provides a full function, flexible, ideal choice for robust industrial control systems. No external programmable analog output solution with only two analog precision resistors or calibration routines are needed to components and meets most requirements for programmable maintain consistent performance in mass production, thereby logic controller (PLC) and distributed control system (DCS) making it ideal for PLC or DCS modules. +15V + 10F 0.1F +1.25V 0.1F +5V + 10F 0.1F V V REFOUT DD SYNCA SYNC V FB DV V AV CC REF DD AD5660-1 SCLK SCLK 0V TO +2.5V V 0V TO 5V OUT V IN V 0V TO 10V SDIN SDIN OUT SYNCB SYNC 5V, 10V GND SCLK SCLK AD5750-1 4mA TO 20mA I 0mA TO 20mA SDIN SDIN OUT 0mA TO 24mA SDO SDO GND AV SS 20mA, 24mA 15V 10F 0.1F + 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 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. 09735-001CN-0203 Circuit Note and Solving the Mystery ofAGN andDGND and Tutorial CIRCUIT DESCRIPTION MT-101, Decoupling Techniques). The AD5750/AD5750-1 are single-channel, low cost, precision voltage/current output drivers developed to meet the Measurements requirements of industrial process control applications. The Integral nonlinearity (INL), differential nonlinearity (DNL), voltage output range can be programmed for the standard and output error are the most important specifications for PLC, output ranges for PLC and DCS applications: 0 V to 5 V, 0 V to DCS, and other process control systems. The AD5750-1 has 10 V, 5 V to +5 V, and 10 V to +10 V. A 20% overrange highly flexible and configurable output ranges that can be setting is also provided for the standard ranges, giving the tailored to meet the needs of the application. Measurements of following options: 0 V to 6 V, 0 V to 12 V, 6 V to +6 V, and INL, DNL, and output error for the circuit are shown in Figure 2, 12 V to +12 V. Figure 3, and Figure 4, respectively. This data was taken at 25C in the voltage output mode using the internal current sense The current output, which is provided on a separate pin, can be resistor. The AD5750-1 range was set for 0 V to 5 V. The test programmed for the ranges of 4 mA to 20 mA, 0 mA to 20 mA, results for all the other ranges are listed in Table 1. 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 5 AD5750/AD5750-1 current output can either source or sink 4 current, it can interface to a wide variety of sensors or actuators. 3 The voltage and current output pins can be tied together to 2 configure the end system as a single-channel output if desired. 1 The AD5660-1 is a single channel, low cost, low power, rail-to- rail voltage buffered output nanoDAC integrated with an on- 0 chip 1.25 V, 5 ppm/C reference. The AD5660-1incorporates a 1 power-on reset circuit to ensure that the DAC output powers up 2 to 0 V and remains there until a valid write command takes place. 3 The interface between the AD5660-1 DAC and the AD5750-1 4 driver is simple and requires no external components. The 5 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 DAC CODE precisely matches the reference input requirement of the Figure 2. INL for 0 V to 5 V Output Range 0.8 AD5750-1. Devices for PLC and DCS applications generally need ESD 0.6 protection and overvoltage protection much higher than the 0.4 formal recommend specifications. The AD5750-1 has integrated ESD protection diodes internal to each pin that can prevent 0.2 damage from a 3 kV transient (Human Body Model). However, 0 the industrial control environment can subject I/O circuits to much higher transients. External 30 V, 600 W transient voltage 0.2 suppressors (TVS), a 50 mA, 30 V PolySwitch, and power Schottky diodes are built into the EVAL-CN0203-SDPZ circuit 0.4 board to provide higher voltage ESD protection, 50 mA 0.6 overcurrent, and 30 V overvoltage protection. The optional external protection circuits are not shown in the simplified 0.8 schematic of Figure 1 but can be found in the detailed schematic (EVAL-CN0203-SDPZ-SCH pdf file) in the CN0203 Design DAC CODE Support package: www.analog.com/CN0203-DesignSupport. Figure 3. DNL for 0 V to 5 V Output Range 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 DNL (LSB) INL (LSB) 0 0 4096 4096 8192 8192 12288 12288 16384 16384 20480 20480 24576 24576 28672 28672 32768 32768 36864 36864 40960 40960 45056 45056 49152 49152 53248 53248 57344 57344 61440 61440 65536 65536 09735-003 09735-002