circuit note cn-0229 devices connected/referenced ad5750-2 industrial current/voltage output driver with programmable ranges ad5686r quad, 16-bit nano dac+ with 2.5 v, 2 ppm/c on-chip reference adum5400 quad-channel isolator with integrated dc-to-dc converter circuits from the lab? reference circuits are engineered and tested for quick and easy system integration to help solve todays analog, mixed-signal, and rf design challenges. for more information and/or support, visit www.analog.com/cn0229 . ADUM1301 triple-channel digital isolator 4-channel, flexible, configurable, voltage, and current output circuit for i/o card and plc applications rev. 0 circuits from the lab? circuits from analog device s have been designed and built by analog devices engineers. standard engineering practices have b een 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 fr om 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 ?2012 analog devices, inc. all rights reserved. av dd av ss dv cc vref vin fault ad5750-2 vout range scale iout range scale gnd sync sclk sdin sdo av dd av ss dv cc fault vout iout gnd av dd av ss dv cc fault vout iout gnd av dd av ss vref vin fault vout iout gnd +15v ?15v +5v_iso +5v adum5400 ADUM1301 sclk sdin sdo sync1 sync2 ldac reset vout iout ad5750-2 output ranges: vout: 0v to 5v, 0v to 10v, 5v, 10v iout: 0ma to 20ma 0ma to 24ma 4ma to 20ma 20ma, 24ma fault indicator +15v ?15v +15v ?15v +15v ?15v ad5750-2 ad5750-2 ad5750-2 sync1 sclk sdin sdo dv cc vref vin vref vin sclk v logic sync sdin sdo input register dac register string dac a buffer v out a input register dac register string dac b buffer v out b input register dac register string dac c buffer v out c input register dac register string dac d buffer v out d v ref gnd v dd 2.5v reference power- down logic power-on reset gain 1/2 interface logic rstsel gain ldac reset ad5686r/ad5685r/ad5684r 10099-001 figure 1. simplified schematic of the analog output circuit (all connections and protection circuits not shown)
cn-0229 circuit note rev. 0 | page 2 of 6 evaluation and design support circuit evaluation boards cn-0229 circuit evaluation board (eval-cn0229-sdpz) system demonstration platform (eval-sdp-cb1z) design and integration iles schematics layout iles bill of materials circit nction and beneits the circuit shown in igure 1 is a multichannel fleible analog output solution with only two analog components and meets most reuirements for multichannel i/o cards programmable logic controllers (plcs) and distributed control systems (dcss) applications. the adr uad 1-bit nanodac with rail- to-rail buffered outputs combined with four of the ad0-2 industrial current/voltage output drivers provide all the typical output current and voltage ranges with 1-bit resolution no missing codes 0.0 linearity and less than 0.1 output error. an ultralow drift (2 ppm/c typical) 2. v voltage reference with high drive capability (up to ma) is integrated in the adr and provides the reference voltage for both the adr and the ad0-2 . this guarantees low noise high accuracy and low temperature drift for the circuit. the adum101 and adum400 provide 200 v rms isolation both on power and all the necessary signals between the analog signal chain and the host controller. or multichannel i/o card applications that need more than 4 channels several adr s can be connected in a daisy chain and no additional eternal digital i/o circuits are reuired. this minimies the cost especially for high channel count isolated applications. the circuit also contains ey features for industrial applications such as on-chip output fault detection pacet error checing (pec) by the crc fleible power-up options and esd protection (4 v for the adr human body model and v for the ad0-2 human body model) maing it an ideal choice for robust industrial control systems. no eternal precision resistors or calibration routines are needed to maintain consistent performance in mass production thereby maing it ideal for plc or dcs modules. circit description the ad0 / ad0-1 / ad0-2 are single-channel low cost precision voltage/current output drivers developed to meet the reuirements of industrial process control applications. the output voltage range can be programmed for the standard output ranges for plc and dcs applications: 0 v to v 0 v to 10 v v to 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 v 0 v to 12 v v to v and 12 v to 12 v. 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 ad0/ ad0-1 / ad0-2 current outputs can either source or sin current they can interface to a wide variety of sensors or actuators. the voltage and current output pins can be connected together to configure the system as a single-channel output if desired. enerally the current output circuit needs at least one precision resistor for current sensing. the current accuracy and temperature drift characteristic of the circuit depends partly on the resistor as well as the reference. the ad0 / ad0-1 / ad0-2 integrates the high precision low drift resistor and still allows the use of an eternal resistor if desired. as a method of improving the stability of the output current over temperature an eternal low drift resistor can be connected to the ret1 and ret2 pins of the ad0 / ad0-1 / ad0-2 instead of the internal resistor. the eternal resistor is selected via the input shift register. if the eternal resistor option is not used leave the ret1 and ret2 pins floating. the adr is a uad 1-bit nanodac with rail-to-rail voltage- buffered outputs integrated with an on-chip 2 ppm/c typical ( ppm/c maimum) 2. v reference. the on-chip reference can drive the reference input of all four ad0-2 s has a low output impedance of 0.0 and can source and sin up to ma. the adr incorporates a power-on reset circuit to ensure that the dac output powers up to 0 v and remains there until a valid write command taes place. the interface between the adr dac and the ad0-2 driver is simple and reuires no eternal voltage reference or precision resistors. the output voltage range of the adr is 0 v to 2. v which matches the input range of the ad0-2 . in addition the reference output voltage of the adr is 2. v which precisely matches the reference input reuirement of the ad0-2 . the adum101 is a triple-channel digital isolator. the adum400 is a uad-channel digital isolator with an integrated isolated dc-to-dc converter. they are both based on i coupler technology and are used to provide isolation between the signal chain and the system microcontroller, with an isolation rating of 2.5 kv rms. the adum5400 provides an isolated 5 v power supply for the 5 v circuits in the secondary side. devices for plc and dcs applications generally need esd protection and overvoltage protection much higher than the formal recommend specifications. the ad566r and the ad5750-2 have internal esd protection diodes to each pin that can prevent damage from a 4 kv ad566r and 3 kv ad5750-2 transient human body model. however, the industrial control environment can subect i/o circuits to much higher transients.
circuit note cn-0229 rev. 0 | page 3 of 6 ?0.3 ?0.2 ?0.1 0 0.1 0.2 0.3 0 4096 8192 12288 16384 20480 24576 28672 32768 36864 40960 45056 49152 53248 57344 61440 65536 dac code dnl (lsb) 10099-003 use the external 54 v, 600 w transient voltage suppressors (tvss) as the first stage of enhanced esd protection. place power schottky diodes in series with a 1 k, 0.5 w resistor on the vsense+ and vsense? pins of the ad5750-2 , and place a 50 ma, 30 v polyswitch on the vout and iout pins. these protective circuits are included in the eval-cn0229-sdpz circuit board to provide 50 v overvoltage protection and 50 ma overcurrent 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-cn0229-sdpz-padsschematic pdf file) in the cn0229 design support package: http://www.analog.com/cn0229-designsupport . construct the circuit on a multilayer printed circuit board (pcb) board with a large area ground plane. use proper layout, grounding, and decoupling techniques to achieve optimum system performance and low emi (see tutor ia l mt-031, grounding data converters and solving the mystery of "agnd" and "dgnd," and tutorial mt-101, decoupling techniques ). figure 3. dnl for 0 v to 5 v output range 0.01 0 0.01 0.02 0 4096 8192 12288 16384 20480 24576 28672 32768 36864 40960 45056 49152 53248 57344 61440 65536 dac code output error (%fsr) 10099-004 measurements integral nonlinearity (inl), differential nonlinearity (dnl), and output error are the most important specifications for plc, dcs, and other process control systems. the ad5750-2 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 25c in the voltage output mode. the ad5750-2 range was set for 0 v to 5 v. the test results for all the other ranges are listed in table 1 . 1.0 0.5 0.0 0 1.0 1.5 0 4096 8192 12288 16384 20480 24576 28672 32768 36864 40960 45056 49152 53248 57344 61440 65536 dac code inl (lsb) 10099-002 figure 4. output error for 0 v to 5 v output range figure 2. inl for 0 v to 5 v output range
cn-0229 circuit note rev. 0 | page 4 of 6 table 1. test results for all output ranges range current sense resistor inl (lsb) linearity (%fsr) output error (%fsr) 0 v to + v dont care 1.3 0.002 0.01 0 v to +10 v dont care 1.1 0.002 0.02 ? v to + v dont care 1.4 0.002 0.02 ?10 v to +10 v dont care 1.2 0.002 0.02 0 v to +6 v dont care 1.9 0.003 0.02 0 v to +12 v dont care 1.4 0.002 0.0 ?6 v to +6 v dont care 1.3 0.002 0.03 ?12 v to +12 v dont care 1.7 0.003 0.0 ?2. v to +2. v dont care 1.3 0.002 0.03 +4 ma to +20 ma internal .3 0.008 0.07 0 ma to +20 ma internal 4.2 0.006 0.06 0 ma to +24 ma internal 2.9 0.004 0.0 ?20 ma to +20 ma internal .4 0.008 0.02 ?24 ma to +24 ma internal 3.9 0.006 0.02 +4 ma to +20ma external 2.0 0.003 0.04 0 ma to +20ma external 1.7 0.003 0.04 0 ma to +24ma external 1.6 0.002 0.04 ?20 ma to +20 ma external 3.7 0.006 0.03 ?24 ma to +24 ma external 4.4 0.007 0.03 +3.92 ma to +20.4 ma internal 1.7 0.014 0.11 0 ma to +20.4 ma internal 2.9 0.006 1.86 0 ma to +24. ma internal 2. 0.00 0.30 the test results shown in table 1 were made at 2c for the first channel of the eval-cn0229-sdpz board powered by an agilent e3631a dc supply and measured with the agilent 34401a digital multimeter. note that the output ranges 3.92 ma to 20.4 ma , 0 ma to 20.4 ma, and 0 ma to 24. ma are all designed to be trimmed by the customer to precisely match the 4 ma to 20 ma, 0 ma to 20 ma, and 0 ma to 24 ma ranges. the 1.86% fsr output error measurement in the 0 ma to 20.4 ma range includes the gain error, which is easily removed by customer calibration. there is a lower dead band about 10 mv referenced to gnd. all the linearity test results were calculated using a reduced code range of 26 to 6,3. for 3.92 ma to 20.4 ma , 0 ma to 20.4 ma, and 0 ma to 24. ma, the lower dead band is larger than other standard ranges, and the measured code range is from 1000 to 6,3. common variations the ad68r (14 bits) and the ad684r (12 bits) are pin- compatible with the ad686r for applications not requiring 16-bit resolution. for applications that require channel-to-channel isolation, single dacs, such as the ad660 (16 bits), the ad640 (14 bits), and the ad620 (12 bits), are good choices. for single-channel applications, see the cn-0202 , cn-0203 , and cn-0204 circuit notes for more details. for multichannel applications, the ad623r (12-bits), ad643r (14-bits), and ad663r (16-bits) are dual nanodacs, and the ad624r (12-bits), ad644r (14-bits), and ad664r (16-bits) are quad nanodacs. the ad628 / ad648/ ad668 are octal 12-/14-/16-bit spi voltage output densedacs with ppm/c on-chip references. the ad70 and ad70-1 drivers are pin-compatible with the ad70-2 . the ad70 can accept 0 v to 4.096 v input with a 4.096 v reference. the ad70-1 can accept a 0 v to 2. v input with a 1.2 v reference. the ad71 is a unipolar analog output driver and can supply a 40 v output using a 0 v avdd supply. circuit evaluation and test equipment needed (equivalents can be substituted) ? ? ? ? ? ? ?
circuit note cn-0229 rev. 0 | page 5 of 6 getting started load the evaluation software by placing the cn-0229 evaluation software cd into the cd drive of the pc. using my computer , locate the drive that contains the evaluation software cd and open the readme file. follow the instructions contained in the readme file for installing and using the evaluation software. functional block diagram figure 5 shows a functional block diagram of the test setup. the eval-cn0229-padsschematic pdf file contains the detailed circuit schematics for the cn-0229 evaluation board. this file is contained in the cn-0229 design support package: http://www.analog.com/cn0229-designsupport . setup connect the 120-pin connector on the eval-cn0229-sdpz circuit board to the con a connector or the con b connector on the eval-sdp-cb1z (sdp) board. use nylon hardware 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. with power to the supply off, connect a +15 v power supply to +15 v pin of cn1, a ?15 v power supply to the ?15 v pin of cn1, and gnd to the gnd pin of cn1. connect +6 v to cn2 the same way. turn on the power supply and then connect the 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-cn0229-sdpz . cn1 cn2 +15v ? figure 5. test setup functional block diagram table 2. umper settings for eval-cn0229-sd pz (bolded values are default settings) jumper 1 descriptions setting function jp1[ch] vsense+ setting shorting shorts vsense+ with vout internally for channel [ch]. opening vsense+ has no connection with vout internally for channel [ch]. jp2[ch] vsense? setting shorting shorts vsense? with gnd internally for channel [ch]. opening vsense? has no connection with gnd internally for channel [ch]. jp3[ch] shorting shorts vout and iout together for channel [ch]. shorts the vout and iout pins opening vout and iout have no connection internally for channel [ch]. jp4[ch] shorting adds an 1 nf comp ensation capacitor for channel [ch]. sets the external compensation capacitor opening removes an 1 nf compensation capacitor for channel [ch]. 1 note: [ch] 1, 2, 3, or 4.
cn-0229 circuit note rev. 0 | page 6 of 6 test after setting up the test equipment, connect the vout pin of cn3 or the iout pin of cn4 to the input of the agilent 34401a. ensure that the cable connection on the front panel of agilent 34401a is correct, depending on the different input signal type (current or voltage). testing the inl, dnl, and output error takes a considerable amount of time because all the ad5686r 16-bit dac levels must be set and measured by the agilent 34401a. 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 agilent 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 output error using industry-standard definitions. for more details on the definitions and how to calculate the inl, dnl, and output error from the measured data, see the ter mi nolo g y s e c t ion of t he ad5686r data sheet and the data conversion handbook , "testing data converters," chapter 5, analog devices . learn more cn-0229 design support package: http://www.analog.com/cn0229-designsupport slattery, colm, derrick hartmann, and li ke, "plc evaluation board simplifies design of industrial process control systems. analog dialogue (april 2009). cn-0202 circuit note, flexible high accuracy, low drift, plc/dcs analog output module . c n-0203 circuit note, flexible plc/dcs analog output module using only two analog components. cn-0204 circuit note, flexible, high voltage, high accuracy, low drift plc/dcs analog output module. 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 - adc and the adum5401 digital isolator , analog devices. cn-0067 circuit note, fully isolated input module based on the ad7793 24-bit - 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. an-0971 recommendations for control of radiated emissions with isopower devices by mark cantrell mt-031 tutorial, grounding data converters and solving the mystery of agnd and dgnd , analog devices. mt-101 tutorial, decoupling techniques , analog devices. wa lt ke ste r, practical design techniques for sensor signal conditioning, analog devices , 1999, isbn 0-916550-20-6 wa lt ke ste r, data conversion handbook , chapter 5, analog devices. data sheets and evaluation boards cn-0229 circuit evaluation board (eval-cn0229-sdpz) system demonstration platform (eval-sdp-cb1z) ad5750-2 data sheet and evaluation board ad5686r data sheet and evaluation board adum5400 data sheet and evaluation board ADUM1301 data sheet and evaluation board revision history 4/12rev. 0: initial version (continued from first page) circuits from the lab circuits are intended only for use with analog devices products and are the i ntellectual 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 otherwi se 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 an d reliable. however, circuits from the lab circuits 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. ?2012 analog devices, inc. all rights reserved. trademarks and registered trademarks are the prop erty of their respective owners. cn10099-0-4/12(0)
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