TCN75 2-Wire Serial Temperature Sensor and Thermal Monitor Features Package Type Solid-State Temperature Sensing SOIC 0.5C Accuracy (Typ.) SDA 1 8 V Operates from -55C to +125C DD Operating Supply Range: 2.7V to 5.5V SCL 2 7 A0 Programmable Trip Point and Hysteresis with TCN75MOA 3 6 A1 INT/CMPTR Power-up Defaults Standard 2-Wire Serial Interface A2 GND 4 5 Thermal Event Alarm Output Functions as Interrupt or Comparator / Thermostat Output MSOP Up to 8 TCN75s may Share the Same Bus SDA Shutdown Mode for Low Standby Power V 8 1 DD Consumption SCL 7 A0 2 5V Tolerant I/O at V =3V TCN75MUA DD 3 6 A1 INT/CMPTR LowPower: 5 4 A2 - 250 A (Typ.) Operating GND -1 A (Typ.) Shutdown Mode 8-Pin SOIC and MSOP Packaging General Description Applications The TCN75 is a serially programmable temperature sensor that notifies the host controller when ambient Thermal Protection for High Performance CPUs temperature exceeds a user programmed set point. Solid-State Thermometer Hysteresis is also programmable. The INT/CMPTR Fire/Heat Alarms output is programmable as either a simple comparator Thermal Management in Electronic Systems: for thermostat operation or as a temperature event - Computers interrupt. Communication with the TCN75 is accomplished via a two-wire bus that is compatible with - Telecom Racks industry standard protocols. This permits reading the - Power Supplies / UPS/ Amplifiers current temperature, programming the set point and Copiers / Office Electronics hysteresis, and configuring the device. Consumer Electronics TheTCN75powersupinComparator mode with a Process Control default set point of 80C with 5C hysteresis. Defaults allow independent operation as a stand-alone thermostat. A shutdown command may be sent via the 2-wire bus to activate the low power Standby mode. Address selection inputs allow up to eight TCN75s to share the same 2-wire bus for multizone monitoring. All registers can be read by the host and the INT/ CMPTR output s polarity is user programmable. Both polled and interrupt driven systems are easily accommodated. Small physical size, low installed cost, and ease of use make the TCN75 an ideal choice for implementing sophisticated system management schemes. 2002 Microchip Technology Inc. DS21490B-page 1TCN75 Device Selection Table Part Number Supply Voltage Package Junction Temperature Range TCN75-3.3MOA 3.3 8-Pin SOIC -55C to +125C TCN75-5.0MOA 5.0 8-Pin SOIC -55C to +125C TCN75-3.3MUA 3.3 8-Pin MSOP -55C to +125C TCN75-5.0MUA 5.0 8-PIn MSOP -55C to +125C Functional Block Diagram INT/CMPTR TCN75 9-Bit Control Logic A/D Converter Temp Sensor Register Set V DD T Configuration SET T Temperature HYST SDA SCL Two Wire Serial Port Interface A 0 A 1 A 2 DS21490B-page 2 2002 Microchip Technology Inc.