The MAX6655/MAX6656 are precise voltage and temperature monitors. The digital thermometer reports the temperature of two remote sensors and its own die temperature. The remote sensors are diode-connected transistors—typically a low-cost, easily mounted 2N3906 PNP type—that replace conventional thermistors or thermocouples. Remote accuracy is ±1°C for multiple transistor manufacturers with no calibration necessary. The remote channels can also measure the die temperature of other ICs, such as microprocessors, that contain a substrate-connected PNP with its collector grounded and its base and emitter available for temperature-sensing purposes. The temperature is digitized with 11-bit resolution.The MAX6655/MAX6656 also measure their own supply voltage and three external voltages with 8-bit resolution. Each voltage input's sensitivity is set to give approximately 3/4-scale output code when the input voltage is at its nominal value. The MAX6655 operates at +5V supply and its second voltage monitor is 3.3V. The MAX6656 operates on a +3.3V supply and its second voltage monitor is 5V.The 2-wire serial interface accepts standard SMBus™ Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the alarm thresholds and to read data. The MAX6655/MAX6656 also provide SMBus alert response and timeout functions. The MAX6655/MAX6656 measure automatically and autonomously, with the conversion rate programmable. The adjustable rate allows the user to control the supply current.In addition to the SMBus active-low ALERT output, the MAX6655/MAX6656 feature an active-low OVERT output, which is used as a temperature reset that remains active only while the temperature is above the maximum temperature limit. The active-low OVERT output is optimal for fan control or for system shutdown.ApplicationsCommunication SystemsComputers: Desktop, Workstation, ServerNotebook ComputersServersThin ClientsWorkstations

The MAX1668/MAX1805/MAX1989 are precise multichannel digital thermometers that report the temperature of all remote sensors and their own packages. The remote sensors are diode-connected transistors—typically low-cost, easily mounted 2N3904 NPN types—that replace conventional thermistors or thermocouples. Remote accuracy is ±3°C for multiple transistor manufacturers, with no calibration needed. The remote channels 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.The MAX1668/MAX1805/MAX1989 are available in small, 16-pin QSOP surface-mount packages. The MAX1989 is also available in a 16-pin TSSOP.ApplicationsCentral Office Telecom EquipmentDesktop/Notebook ComputersIndustrial ControlsLAN ServersMultichip ModulesTest and Measurement Equipment

The MAX6604 high-precision temperature sensor is designed for thermal monitoring functions in DDR memory modules. The device is readable and programmable through the 2-wire SMBus/I²C-compatible interface. Three address inputs set the bus address for the temperature sensor to provide up to eight devices on one bus.The internal thermal sensor continuously monitors the temperature and updates the temperature data eight times per second. The master can read the temperature data at any time. Since the thermal sensor is located on the memory module, temperature data recorded accurately represents the temperature of the components on the module. Consequently, the MAX6604 provides a much more accurate measurement of module temperature than techniques involving temperature sensors on the motherboard. In addition, the device responds more quickly to temperature changes on the module than a motherboard sensor.The MAX6604 also features an interrupt-output indicator for temperature-threshold monitoring. The threshold levels are programmable through the digital interface.The MAX6604 operates from -20°C to +125°C, and is available in JEDEC-standard 8-pin TSSOP and 8-pin TDFN (2mm x 3mm) packages.ApplicationsDesktop ComputersMemory ModulesNetworking EquipmentNotebook ComputersWorkstations

The MAX6604 high-precision temperature sensor is designed for thermal monitoring functions in DDR memory modules. The device is readable and programmable through the 2-wire SMBus/I²C-compatible interface. Three address inputs set the bus address for the temperature sensor to provide up to eight devices on one bus.The internal thermal sensor continuously monitors the temperature and updates the temperature data eight times per second. The master can read the temperature data at any time. Since the thermal sensor is located on the memory module, temperature data recorded accurately represents the temperature of the components on the module. Consequently, the MAX6604 provides a much more accurate measurement of module temperature than techniques involving temperature sensors on the motherboard. In addition, the device responds more quickly to temperature changes on the module than a motherboard sensor.The MAX6604 also features an interrupt-output indicator for temperature-threshold monitoring. The threshold levels are programmable through the digital interface.The MAX6604 operates from -20°C to +125°C, and is available in JEDEC-standard 8-pin TSSOP and 8-pin TDFN (2mm x 3mm) packages.ApplicationsDesktop ComputersMemory ModulesNetworking EquipmentNotebook ComputersWorkstations

The MAX6689 precision multichannel temperature sensor monitors its own temperature and the temperatures of up to six external diode-connected transistors. All temperature channels have programmable alert thresholds. Channels 1, 4, 5, and 6 also have programmable overtemperature thresholds. When the measured temperature of a channel exceeds the respective threshold, a status bit is set in one of the status registers. Two open-drain outputs, active-low OVERT and active-low ALERT, assert corresponding to these bits in the status register.The 2-wire serial interface supports the standard system management bus (SMBus™) protocols: write byte, read byte, send byte, and receive byte for reading the temperature data and programming the alarm thresholds.The MAX6689 is specified for an operating temperature range of -40°C to +125°C and is available in 20-pin QSOP and TSSOP packages.ApplicationsDesktop ComputersNotebook ComputersServersWorkstations

The MAX31722/MAX31723 digital thermometers and thermostats with an SPI/3-wire interface provide temperature readings that indicate the device temperature. No additional components are required; the devices are truly temperature-to-digital converters. Temperature readings are communicated from the device over an SPI interface or a 3-wire serial interface. The choice of interface is selectable by the user. For applications that require greater temperature resolution, the user can adjust the readout resolution from 9 to 12 bits. This is particularly useful in applications where thermal runaway conditions must be detected quickly. The thermostat has a dedicated open-drain output (active-low TOUT). Two thermostat operating modes, comparator and interrupt, control thermostat operation based on user-defined nonvolatile trip points (THIGH and TLOW). Both devices feature a 1.7V to 3.7V supply rail.ApplicationsAny Thermally Sensitive SystemsCellular Base StationsIndustrial EquipmentNetworking Equipment

The MAX6501–MAX6504 low-cost, fully integrated temperature switches assert a logic signal when their die temperature crosses a factory-programmed threshold. Operating from a +2.7V to +5.5V supply, these devices feature two on-chip, temperature-dependent voltage references and a comparator. They are available with factory-trimmed temperature trip thresholds from -45°C to +125°C in 10°C increments, and are accurate to ±0.5°C (typ) or ±6°C (max). These devices require no external components and typically consume 30µA supply current. Hysteresis is pin-selectable at 2°C or 10°C.The MAX6501/MAX6503 have an active-low, open-drain output intended to interface with a microprocessor (µP) reset input. The MAX6502/MAX6504 have an active-high, push-pull output intended to directly drive fan-control logic. The MAX6501/MAX6502 are offered with hot-temperature thresholds (+35°C to +125°C), asserting when the temperature is above the threshold. The MAX6503/MAX6504 are offered with cold-temperature thresholds (-45°C to +15°C), asserting when the temperature is below the threshold.The MAX6501–MAX6504 are offered in eight standard temperature versions; contact the factory for pricing and availability of nonstandard temperature versions. They are available in 5-pin SOT23 package.ApplicationsµP Temperature Monitoring in High-Speed ComputersFan ControlTemperature AlarmsTemperature Control

The MAX6501–MAX6504 low-cost, fully integrated temperature switches assert a logic signal when their die temperature crosses a factory-programmed threshold. Operating from a +2.7V to +5.5V supply, these devices feature two on-chip, temperature-dependent voltage references and a comparator. They are available with factory-trimmed temperature trip thresholds from -45°C to +125°C in 10°C increments, and are accurate to ±0.5°C (typ) or ±6°C (max). These devices require no external components and typically consume 30µA supply current. Hysteresis is pin-selectable at 2°C or 10°C.The MAX6501/MAX6503 have an active-low, open-drain output intended to interface with a microprocessor (µP) reset input. The MAX6502/MAX6504 have an active-high, push-pull output intended to directly drive fan-control logic. The MAX6501/MAX6502 are offered with hot-temperature thresholds (+35°C to +125°C), asserting when the temperature is above the threshold. The MAX6503/MAX6504 are offered with cold-temperature thresholds (-45°C to +15°C), asserting when the temperature is below the threshold.The MAX6501–MAX6504 are offered in eight standard temperature versions; contact the factory for pricing and availability of nonstandard temperature versions. They are available in 5-pin SOT23 package.ApplicationsµP Temperature Monitoring in High-Speed ComputersFan ControlTemperature AlarmsTemperature Control

The MAX31875 is a ±1°C-accurate local temperature sensor with I2C/SMBus interface. The combination of tinypackage and excellent temperature measurement accuracymakes this product ideal for a variety of equipment.The I2C/SMBus-compatible serial interface accepts standard write byte, read byte, send byte, and receive byte commands to read the temperature data and configure the behavior of the sensor. Bus timeout resets the interface if the clock is low for more than 30ms (nominal). PEC helps to avoid communication errors when used with a master that supports this feature.The MAX31875 is available in a 4-bump, wafer-level package (WLP) and operates over the -50°C to +150°C temperature range. Design Solution: Cool Down with a Smaller, Lower Power Temperature Sensor ›ApplicationsBattery-Powered EquipmentData Communications EquipmentHandheld ElectronicsIndustrial EquipmentServers

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