MAX1618

The MAX1618 precise digital thermometer reports the temperature of a remote sensor. The remote sensor is a diode-connected transistor-typically a low-cost, easily mounted 2N3904 NPN type-that replaces conventional thermistors or thermocouples. Remote accuracy is ±3°C for multiple transistor manufacturers, with no calibration needed. The MAX1618 can also measure the die temperature of other ICs, such as microprocessors, that contain an on-chip, diode-connected transistor.

The 2-wire serial interface accepts standard System Management Bus (SMBus™) Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the alarm thresholds and to read temperature data. The data format is 7 bits plus sign, with each bit corresponding to 1°C, in two's complement format. Measurements can be done automatically and autonomously, with the 16Hz conversion rate or programmed to operate in a single-shot mode.

The thermostat mode configures the active-low ALERT output as an interrupt or as a temperature reset that remains active only while the temperature is above the maximum temperature limit or below the minimum temperature limit. The active-low ALERT output polarity in thermostat mode can be configured for active high or active low. Fan control is implemented using this active-low ALERT output.

The MAX1618 is available in a small (1.1mm high) 10-pin µMAX package.

Applications

• Central Office Telecom Equipment
• Computers: Desktop, Workstation, Server
• Industrial Controls
• LAN Servers
• Multichip Modules
• Smart Battery Packs/Chargers
• Test and Measurement Equipment