3-Channel Remote Temperature Sensor

The MAX31730 temperature sensor monitors its own temperature and the temperatures of three external diode-connected transistors. The operating supply voltage is from 3.0V to 3.6V. Resistance cancellation compensates for high series resistance in circuit-board traces and the external thermal diode, while beta compensation corrects for temperature-measurement errors due to low-beta sensing transistors.

All temperature channels have programmable temperature thresholds. When the measured temperature of a channel crosses the respective threshold, a status bit is set in the thermal status registers and the open-drain active-low THERM output asserts. A highest temperature register allows the master to obtain the temperature of the hottest channel.

The 2-wire serial interface accepts SMBus protocols (write byte, read byte, send byte, and receive byte) for reading the temperature data and programming the temperature thresholds. Any one of eight available slave addresses can be selected using the address selection input (ADD), which can be connected to ground or connected to a grounded resistor.

The MAX31730 supports 3.0V to 3.6V operation and is specified for a -40°C to +125°C operating temperature range and is available in a 10-pin µMAX® and a 12-pin, 3mm x 3mm TDFN package.

Applications

* Communications Equipment * CPU, FPGA, and ASIC Die Temperature Monitoring * Servers

* Highest Temperature Register Simplifies and Speeds Overtemperature Notification

* Accurate Temperature Measurement Helps Designers Meet Error Budgets

* 12-Bit, 0.0625°C Resolution

* ±1°C Remote Temperature-Measurement Accuracy (0°C to +100°C)

* -64°C to +150°C Remote Temperature-Measurement Range

* Resistance Cancellation for Remote Channels

* Compensation for Low Beta Transistors

* Programmable Temperature Thresholds

* Integration Reduces Cost, Board Area, Power-Supply Current, and Slave Address Usage

* One Local and Three Remote Temperature-Sensing Channels

* Eight Selectable Slave Addresses

* Flexible SMBus/I2C Bus Interfaces to a Variety of Microcontrollers