Isolated Process Current Input 7B32 FEATURES FUNCTIONAL BLOCK DIAGRAM Interfaces, amplifies and filters a process-current input . Module provides a precision output of either +1 V to +5 V or 0 V to +10 V, linear with temperature. Process-current input signals are measured by reading the voltage across an internal 200Ω protected resistor. All 7B32 series modules are mix-and-match and Hot Swappable. APPLICATIONS Industrial signal conditioning Industrial signal isolation Industrial signal filtering PRODUCT OVERVIEW The 7B Series of signal conditioners feature small size, low cost and a wide output voltage range for a variety of applications including process control and factory-floor environments. The single-channel 7B modules accept inputs from a range of transducers and are fully rated over the extended -40oC to +85oC industrial temperature range. All 7B Series modules are rated for a nominal power supply input of +24 VDC; and, for maximum flexibility, they will accept supply voltages in the +14 VDC to +35 VDC range. The input modules, with the exception of the 7B21, provide a high-level output voltage that is factory configured for either the +1 V to +5 V or 0 V to +10 V range. The 7B21 is a unity gain, isolated input module with an input/output range of +10V. Output modules are available that provide either isolated process current or isolated bipolar voltage output. Model 7B39 converts either a +1 V to +5 V input to a 4 to 20 mA output or a 0 V to +10 V input to a 0-20 mA output. The input/output ranges of the 7B39 are factory configured. The 7B22 is a unity gain module that provides an isolated +10V output signal. All modules have a universal pinout and may be readily hot-swapped under full power without disrupting field wiring. Each module accepts analog transducer signals and transfers them to a process control or factory data collection system without the inherent noise, non-linearity, drift and extraneous voltages which frequently accompany the signals. Figure 1. 7B32 Functional Block Diagram The modules feature a maximum nonlinearity of +0.02% and are factory calibrated to guarantee a maximum accuracy specification of +0.1%. The 7B Series offers up to 1500 V rms continuous common mode voltage isolation and 120 V rms of field wiring input protection. The power supplies necessary to drive each of the individual module’s input circuitry are internally isolated, enabling the 7B Series modules to offer true channel-to-channel isolation of the input signals. The modules directly accept analog signals from thermocouples, RTDs, current loop powered transmitters, and other process control signals. The 7B Series modules amplify, linearize, isolate, protect and convert the transducer output signals to standardized analog inputs for high-level analog I/O subsystems. The 7B Series Subsystem consists of 19-inch rackcompatible hardware (model AC 1363), with universal mounting backplane and a family of plug-in (up to 16 per backplane) input and output signal conditioning modules. Four, eight-, and sixteen-channel backplanes are available. Each backplane incorporates screw terminals for easy power connections and field wiring, and includes a 25-pin D-type connector for interfacing the high-level single-ended voltage outputs to the user’s equipment. Gold-plated sockets are provided on each channel of the backplane to ensure the reliability of each module’s electrical connection. 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 that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective companies. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. www.analog.com Tel: 781.329.4700 Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved. 7B32 GENERAL DESCRIPTION isolation(1500 V rms input-to-output and power). Isolated front-end circuitry power is supplied by a DC/DC converter. The output section contains a two-pole low pass filter (-3 dB @ 100 Hz), a buffer amplifier and a power oscillator. The two-pole output filter and subsequent buffer ensures that a low noise, low impedance (<1Ω) signal is available at the output to drive loads to 2 kΩ minimum The 7B32 is a single-channel signal conditioning module that interfaces, amplifies and filters a process-current input and provides a protected precision output voltage of either +1V to +5 V or 0 V to +10 V. Process-current input signals are measured by reading the voltage across an internal 200Ω protected resistor. Model 7B32 features a nonlinearity of +0.02% maximum and an accuracy of +0.1% maximum (+0.01% typical). To accurately measure low level signals in electrically noisy environments, 1500 V rms of galvanic transformer-based isolation with a common mode rejection (CMR) of 105 dB @ 50/60 Hz is provided. Rated to operate with a nominal +24 VDC supply, Model 7B32 is mix-and-match and hot-swappable with other 7B Series input modules, so it can be inserted or removed from any socket in the same backplane without disturbing system power. The floating current input of Model 7B32 is fully protected up to 120 V rms line voltage. A one-pole 100 Hz filter preconditions the voltage signal across the 200W protected input resistor prior to amplification by a low drift amplifier. Amplitude modulation is used to implement transformer Figure 2 Rev. 0 | Page 2 of 8 7B32 7B32 Models Available Model Input Range Output Range 7B32-01-1 +4 mA to +20 mA +1 V to +5 V 7B32-01-2 0 mA to +20 mA 0 V to +10 V 7B32 Specifications (typical @ +23°C ±5°C and Vs = +24 V dc) Description Model 7B32 Input Range1 Standard Ranges 4 mA to 20 mA; 0 mA to 20 mA (Refer to Model Table) Custom Ranges Not Available* Output Range Options (RL > 2 kΩ) +1 V to +5 V or 0 V to +10 V Accuracy1 Initial @ +25°C ±0.01% Span (±0.1% Span, maximum) Nonlinearity2 ±0.02% Span, maximum Input Offset vs. Temperature N/A3 Span vs. Temperature ±35 ppm/°C Output Offset vs. Temperature ±0.003% Span/°C Input Resistance Power ON 200 Ω Power OFF 200 Ω, minimum Output Noise 5 MHz Bandwidth 6 mV peak 10 Hz to 100 kHz Bandwidth 0.4 mV rms 0.1 Hz to 10 Hz Bandwidth 4 µV peak Bandwidth, -3 dB 100 Hz Output Rise Time, 10% to 90% Span 10 ms Common-Mode Voltage (CMV) Input-to-Output and Power 1500 V ms, continuous Common Mode Rejection (CMR) Input-to-Output and Power @ 50/60 Hz 105 dB Input Protection 120 V rms, continuous ±35 V dc, continuous Input Transient Protection ANSI/IEEE C376.90.1-1989 IEEE-STD 472 IEC 255-4, Class II Rev. 0 | Page 3 of 8 7B32 Output Resistance <1Ω Voltage Output Protection Continuous Short to Ground Power Supply Voltage Range, Operating +14 V dc to +35 V dc Current +25 mA, maximum Sensitivity ±0.0001%/% of Vs Mechanical Dimensions 1.663" x 2.11" x 0.563" (42.24 mm x 53.6 mm x 14.3 mm) Weight 60 grams Environmental Temperature Range Operating -40°C to +85°C Storage -40°C to +85°C Relative Humidity, 24 hours 0 to 90% @ +60°C non-condensing ESD Sensitivity IEC 801-2, Level 2 RFI Susceptibility ±0.5% Span error @ 400 MHz, 5 Watt, 3 ft Warm-up time required to meet specifications is approximately 10 minutes. * Contact factory for OEM requirements. 1 Includes the combined effects of repeatability, hysteresis, and nonlinearity. 2 Nonlinearity is calculated using best-fit straight line method. 3 Vz is the nominal input voltage that results in a 0 V output. Specifications subject to change without notice. Rev. 0 | Page 4 of 8 7B32 PIN CONFIGURATIONS AND FUNCTIONAL DESCRIPTIONS Figure 3 7B32 Input Field Connections Table 1. Pin Function Descriptions— Pin No. 0 1 2 3 4 5 Input Module Function Output Module Function SENSOR INPUT INPUT HIGH INPUT LOW POWER SUPPLY (DC) OUTPUT VOLTAGE OUTPUT & POWER COMMON NOT USED OUTPUT HIGH OUTPUT LOW POWER SUPPLY (DC) INPUT VOLTAGE INPUT AND POWER COMMON Figure 4 . Model 7B Series Module, with pin-out assignments. ESD CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Rev. 0 | Page 5 of 8 7B32 OUTLINE DIMENSIONS Figure 5. Outline Dimensions Rev. 0 | Page 6 of 8 7B32 NOTES Rev. 0 | Page 7 of 8 7B32 NOTES © 2004 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective companies. D05174-0-10/04(0) Rev. 0 | Page 8 of 8