Four-Channel, Isolated Thermocouple/mV Conditioners
Models 2B54/2B55
FEATURES Low Cost Per Channel Wide Input Span Range: 5mV to 100mV (2B54) 50mV to 5V (2B55) Pin Compatible with 2B34 RTD Conditioner High CMV Isolation: 1000V dc; CMR = 156dB min @ 60Hz Low Input Offset Voltage Drift: 1V/C max (2B54B) Low Gain Drift. 25ppm/C max (2B54B) Low Nonlinearity: 0.02% max (0.012% typ) Normal Mode Input Protection (130V rms) and Filtering Channel Multiplexing: 400 chan/sec Scanning Speed Solid State Reliability APPLICATIONS Multichannel Thermocouple Temperature Measurements Low and High Level Data Acquisition Systems Industrial Measurement and Control Systems GENERAL DESCRIPTION Models 2B54 and 2B55 are low cost, high performance, four-channel signal conditioners. Both models are functionally complete, providing input protection, isolation and common mode rejection, multiplexing, filtering and amplification. The 2B54 has been designed to condition low level signals (5mV to 100mV), like those generated by thermocouples or strain gages, in the presence of high common mode voltages. The 2B55 is optimized to condition 50mV to 5V or 4 to 20mA transmitter signals as inputs. The four-channel structure of both models results in significant cost and size reduction. The high performance of the 2B54 and 2B55 is accomplished by the use of reliable transformer isolation techniques and an amplifier-perchannel architecture. Each of the input channels is galvanically isolated (1000V dc) from the other input channels and from output ground. The amplifier-per-channel structure is used to obtain low input drift (1V/C max, 2B54B), high common mode rejection (156dB @ 60Hz), and very stable gain (25ppm/C max). Other key features include low input noise (1V p-p), low nonlinearity (0.02% max) and open-thermocouple detection (2B54). APPLICATIONS Models 2B54 and 2B55 were designed to serve as a superior alternative to the relay multiplexing circuits used in multi-channel data acquisition systems, computer interface systems, process signal isolators, and temperature measurement and control instrumentation. Advantages over relay circuits include functional versatility, superior performance, and solid state reliability. Both models are also pin compatible with the 2B34, four-channel RTD/strain gage conditioner. In thermocouple temperature measurement applications, outstanding low drift, high noise rejection, high throughput and 1000V isolation make the 2B54 a natural choice over flying capacitor multiplexers in conditioning any thermocouple type. 2B54/2B55 FUNCTIONAL BLOCK DIAGRAM
When cold junction compensation is required in measurement of temperature with thermocouples, the 2B54 may be used directly with the model 2B56 Universal Cold junction Compensator. DESIGN FEATURES AND USER BENEFITS High Reliability: To assure high reliability and provide isolation protection to electronic instrumentation, reliable transformer isolation and solid state switching are used. Both models have been conservatively designed to meet the IEEE standard for Transient Voltage Protection (472-19 74: SWC) and offer 130V rms normal mode input protection. High Noise Rejection: To preserve high system accuracy in electrically noisy industrial environments, the 2B54 and 2B55 provide excellent common mode noise rejection, RFI/EMI immunity, and low pass filtering for rejection of series mode noise and 50Hz/60Hz pickup. Ease of Use: The multichannel, functionally complete design in a compact (2" X 4" X 0.4") module, assures case of use, conserves board space and eliminates the need for a number of discrete components necessary in relay multiplexing circuits. Low Cost: The 2B54 and 2B55 offer the lowest cost per channel for isolated. solid state. low level signal conditioners.
Information furnished by Intronics is believed to be accurate and reliable. However, no responsibility is assumed by Intronics 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 Intronics.
1400 Providence Highway, Building #2 Norwood, MA 02062 Phone (781) 551-5500 FAX (781) 551-5555 www.intronicspower.com
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