±1°C, SMBus-Compatible Remote/Local Temperature Sensor with Overtemperature Alarm

The MAX6642 precise, two-channel digital temperature sensor accurately measures the temperature of its own die and a remote PN junction and reports the temperature data over a 2-wire serial interface. The remote PN junction is typically a substrate PNP transistor on the die of a CPU, ASIC, GPU, or FPGA. The remote PN junction can also be a discrete diode-connected small-signal transistor.

The 2-wire serial interface accepts standard system management bus (SMBus™), Write Byte, Read Byte, Send Byte, and Receive Byte commands to read the temperature data and to program the alarm thresholds. To enhance system reliability, the MAX6642 includes an SMBus timeout. The temperature data format is 10 bits with the least significant bit (LSB) corresponding to +0.25°C. The active-low ALERT output asserts when the local or remote overtemperature thresholds are violated. A fault queue can be used to prevent the active-low ALERT output from setting until two consecutive faults have been detected.

Measurements can be done autonomously or in a single-shot mode.

Remote accuracy is ±1°C maximum error between +60°C and +100°C. The MAX6642 operates from -40°C to +125°C, and measures remote temperatures between 0°C and +150°C. The MAX6642 is available in a 6-pin TDFN package with an exposed pad.

Applications

* Desktop Computers * Graphic Cards * Notebook Computers * Servers * Test and Measurement Equipment * Thin Clients * Workstations

* Integrated Temperature Sensor Enables Simultaneous Dual Temperature (Remote and Local) Measurements

* Remote Accuracy ±1°C

* Local Accuracy ±2°C from +60°C to +100°C

* Measures Remote Temperature up to +150°C

* 0.25°C Resolution

* Dual Zone Monitoring Automates Over-Temperature Alarms

* Programmable Remote/Local Temperature Thresholds

* ALERT Output

* Small Footprint

* 3mm x 3mm TDFN Package with Exposed Pad

* Low Thermal Mass Reduces Measurement Latency

* SMBus/I2C Address Hardwired