Building automation equipment monitors and controls environmental systems within a building, including heating, ventilation and air conditioning (HVAC); security video, alarms and access control; fire and safety; metering; and, lighting.
Thermocouples and resistance temperature detectors (RTDs) are the most common industrial temperature sensors due to their ability to handle very wide temperature ranges. However, interfacing to these devices is not always easy. They must be properly biased and their signals properly linearized to realize their maximum accuracy and precision. Any loss of signal from these sensors can be a critical problem since they are usually an integral part of the temperature control loop. To help our customers realize simple and reliable solutions to these challenges, we have developed single-chip sensor digitizer solutions for both thermocouples and RTDs. The solutions bias the sensors, handle the cold junction compensation needed for thermocouples, have many built-in fault detections, and provide digital outputs.
Many building automation systems use RS-485/RS-422 transceivers as the physical media layer for communications between the building automation controller and the remotely managed sensors and actuators. RS-485/RS-422 devices use relatively low-cost twisted-pair wiring, and offer fairly high-speed communications over long distances, up to 4000 ft.— enough to support direct communications links in most buildings.
The MAX17681 is a high-voltage, high efficiency, iso-buck DC-DC converter designed to provide isolated power up to 5W. The device operates over a wide 4.5V to 42V input and uses primary-side feedback to regulate the output voltage.
A simple and complete solution, this RTD-to-Digital converter quickly provides a digital temperature reading, ideal for industrial and medical applications.
2.75kVRMS Isolated 500kbps/25Mbps Full-Duplex RS-485/RS-422 Transceivers with ±35kV ESD Protection and Integrated Transformer Driver
Precision Thermocouple to Digital Converter with Linearization
Large modern buildings often feature building automation controllers. These controllers often have an architecture similar to that of a programmable logic controller (PLC).
PLC solutions are suitable for use in these controllers.