rev. 0 information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of analog devices. a model 5b42 one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781/329-4700 world wide web site: http://www.analog.com fax: 781/326-8703 ? analog devices, inc., 1997 process current input module functional block diagram general description model 5b42 interfaces with 2-wire transmitters to convert their 4-to-20 ma process current signal into a high accuracy output of +1 v to +5 v or +2 v to +10 v. the module provides 1500 v isolation with 140 db cmr, 20 v regulated loop power (at a 4-to-20 ma loop current), signal filtering, and input protection agai nst accidental line voltage connection. the industry standard 5b series encapsulated plug-in modular package is compatible with all 5b backplanes. modules are powered by +5 v dc, 5%. signal isolation is provided by transformer coupling using a propri- etary technique for linear, stable performance. a demodulator on the output side of the signal transformer recovers the input signal, which is filtered and buffered to provide an accurate, low impedance, low noise output. features accepts 4-to-20 ma process current input signal provides isolation and regulated 20 v dc loop power for nonisolated 2-wire transmitters +1 v to +5 v or +2 v to +10 v output 1500 v rms input/output and input/power isolation 250 v rms output/power isolation 140 db common-mode rejection 100 hz signal bandwidth accuracy: 6 0.05% linearity: 6 0.01% 240 v rms field wiring protection protected internal current sense resistor ansi/ieee c37.90.1-1989 transient protection csa, fm and ce approvals true three-port isolation includes common-mode voltage of: 1500 v rms between input and output, and between input and power; 250 v rms between output and power. accurate performance is maintained over a wide C40 c to +85 c operating temperature range. the 5b42s low drift design achieves an output offset drift of only 5 m v/ c and gain drift of 25 ppm/ c. the 5b42 offers significant advantages over signal condition- ers that require an external current sense resistor. an external resistor is not protected from accidental connection to ac line voltages, and its error tolerance must be added to the conditioners specified errors. the 5b42 is trimmed and specified including its internal 25 w current-sense input resistor. the 5b42 signal input, loop supply and the sense resistor are all protected against accidental appli- cation of voltages, such as an ac power line, up to 240 v rms continuous. there is no need to install an external resistor on the backplane, but if one is installed, it has no effect on the 5b42 performance. the m odule has a C3 db bandwidth of 100 hz, an optimized 5-pole signal filter with low overshoot and exceptional output noise performance of 200 m v peak-to-peak at 100 khz bandwidth. the 5b42 logic-controlled series output switch eliminates the need for external multiplexing in many applications. this low output resistance switch is controlled by an active low enable input. when the output switch is not used, ground the enable input to i/o common to turn on the switch. active 4-pole lpf isolated fieldside power v out i/o com rd en +5v pwr com 2-wire transmitter 5b backplane 5b42 power oscillator amp isolated output- side power 4 6 5 3 lpf protection regulated loop supply 17 16 isolation 22 20 19 isolated output section isolated input section + C C + 25 v +exc +in 4 3 2 1 + C
C2C rev. 0 model 5b42Cspecifications c3210C2C10/97 printed in u.s.a. model 5b42 input standard ranges 4 ma to 20 ma (see table i) custom range limits 0 ma to 20 ma (see table ii) input resistor 1 25 w loop supply voltage 20 v @ 4 ma to 20 ma normal-mode rejection (nmr) C3 db @ 100 hz 90 db per decade above 100 hz input/excitation/sense resistor protection continuous 240 v rms max transient ansi/ieee c37.90.1C1989 common-mode voltage (cmv) input-to-output, continuous 1500 v rms, max input-to-power, continuous 1500 v rms, max power-to-output, continuous 2 250 v rms, max common-mode rejection (cmr) 50 hz/60 hz 3 140 db accuracy initial @ +25 c 4 0.05% span 4 m a rti 5 nonlinearity 0.01% span stability vs. temperature (C40 c to +85 c) input offset 0.5 m v/ c output offset 5 m v/ c gain 25 ppm of reading/ c output range (see tables i and ii) 5b42-01 +1 v to + 5 v 5b42-02 +2 v to +10 v resistance 25 w bandwidth, C3 db 100 hz step response time (90% span) 4 ms noise input, 0.1 hz to 10 hz 10 na rms output, 100 khz 200 m v pk-pk protection continuous short to ground current limit 20 ma enable time (c load = 0 pf to 2000 pf) 6 m s to 1 mv of v out enable control max logic 0 +0.8 v min logic 1 +2.4 v max logic 1 +36 v input current 0, 1 0.5 m a power supply voltage, rated performance +5 v dc 5% current @ transmiter load of 20 ma 200 ma @ transmitter load of 4 ma 100 ma sensitivity 1 m v/% rti 5 case size, maximum 2.275" 2.325" 0.595" (57.8 mm 59.1 mm 15.1 mm) weight 70 grams environmental temperature range, rated performance C40 c to +85 c storage temperature C40 c to +85 c relative humidity 0% to 93% @ +40 c, noncondensing rfi susceptibility 0.5% span error @ 400 mhz, 5 w, 3' notes 1 a precision 25 w current-sense input resistor is internal to the 5b42. 2 the users board layout must separate power ground from i/o common and when the 5b42 output switch is not used, ground the enable input to i/o common. power-to-output cmv is not available when the 5b42 is installed on a 5b series backplane. 3 the use of shielded cable from the signal source to the 5b42 inputs is recommended to maintain cmr performance. 4 includes the combined effects of repeatability, hysteresis and nonlinearity. 5 referenced to input. specifications subject to change without notice. (typical @ +25 8 c and v s = +5 v dc) table i. standard model input/output ranges* model input range output range 5b42-01 4 ma to 20 ma +1 v to +5 v 5b42-02 4 ma to 20 ma +2 v to +10 v *custom input/output ranges are available. see table ii. table ii. custom model ordering guide order model: 5b42-custom plus customer specified information customer specified information: input range output range low high available range limit limit 0 ma to 20 ma* 0 v 10 v *there is no loop power supplied by the 5b42 at 0 ma input.
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