ELM341

ELM341 Low Power Thermostat Description The ELM341 is a complete temperature measurement and control system in an 8 pin package. It automatically reverts to a very low power sleep mode between measurements, making it suitable for battery operation. This integrated circuit is designed to compare two resistances and drive an output pin depending on the relative value of each. Typically, one of the resistors will be an NTC thermistor, and the other one will be a temperature independent resistor (whether fixed or variable). When the magnitude of the resistance connected to pin 2 exceeds the value of the resistance connected to pin 3, the output pin will be driven to a high state. Hysteresis maintains the output in that state until the relative values differ by approximately 8% (or typically 2°C for a 10KΩ thermistor). To reduce the possibility of sporadic outputs, a condition must exist for three successive cycles, or 6 seconds, before the output pin can change state. Applications Backup thermostats Under or over temperature alarm circuits Features Low power CMOS design Wide supply range - 3.0 to 5.5 volt operation Built-in proportional hysteresis Measurement in progress output Time delay on operate improves noise immunity Internal pullup resistor on the reset input High current drive outputs - up to 25 mA Sleep mode reduces power requirements Connection Diagram PDIP and SOIC (top view) VDD 1 R1 2 R2 3 reset 4 8 VSS 7 Out 6 MIP 5 Cap Block Diagram reset ...