The DS75LV low-voltage (1.7V to 3.7V) digital thermometer and thermostat provides 9-, 10-, 11-, or 12-bit digital temperature readings over a -55°C to +125°C range with ±2°C accuracy over a -25°C to +100°C range. At power-up, the DS75LV defaults to 9-bit resolution for software compatibility with the LM75. Communication with the DS75LV is achieved through a simple 2-wire serial interface. The DS75LV thermostat has a dedicated open-drain output (O.S.) and programmable fault tolerance, which allows the user to define the number of consecutive error conditions that must occur before O.S is activated. There are two thermostatic operating modes that control thermostat operation based on user-defined trip-points (TOS and THYST).ApplicationsAny Thermally Sensitive SystemCellular Base StationsOffice EquipmentPersonal Computers

The DS1621 Digital Thermometer and Thermostat provides 9-bit temperature readings, which indicate the temperature of the device. The thermal alarm output, TOUT is active when the temperature of the device exceeds a user-defined temperature TH. The output remains active until the temperature drops below user defined temperature TL, allowing for any hysteresis necessary.User-defined temperature settings are stored in nonvolatile memory so parts may be programmed prior to insertion in a system. Temperature settings and temperature readings are all communicated to/from the DS1621 over a simple 2-wire serial interface.ApplicationsMedicalNetworkingPersonal ComputingRouters/SwitchesTest Measurement SystemsWireless Base Stations

The DS75 digital thermometer and thermostat provides 9, 10, 11, or 12-bit digital temperature readings over a -55°C to +125°C range with ±2°C accuracy over a -25°C to +100°C range. At power-up, the DS75 defaults to 9-bit resolution for software compatibility with the LM75. Communication with the DS75 is achieved via a simple 2-wire serial interface. Three address pins allow up to eight DS75 devices to operate on the same 2-wire bus, which greatly simplifies distributed temperature sensing applications. The DS75 thermostat has a dedicated open-drain output (O.S.) and programmable fault tolerance, which allows the user to define the number of consecutive error conditions that must occur before O.S is activated. There are two thermostatic operating modes that control thermostat operation based on user-defined trip-points (TOS and THYST).A block diagram of the DS75 is shown in Figure 1 and detailed pin descriptions are given in Table 2.ApplicationsAny Thermally Sensitive SystemCell Phone Base Stations Office EquipmentPersonal Computing

The MAX6697 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 MAX6697 is specified for an operating temperature range of -40°C to +125°C and is available in 20-pin QSOP and 20-pin TSSOP packages.ApplicationsDesktop ComputersNotebook ComputersServersWorkstations

The MAX1617 is a precise digital thermometer that reports the temperature of both a remote sensor and its own package. 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 remote channel 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 conversion rate programmed by the user or programmed to operate in a single-shot mode. The adjustable rate allows the user to control the supply-current drain.The MAX1617 is available in a small, 16-pin QSOP surface-mount package.ApplicationsCentral Office Telecom EquipmentComputers: Desktop, Workstation, ServerIndustrial ControlsLAN ServersMultichip ModulesSmart Battery Packs/ChargersTest and Measurement Equipment

The DS1629 digital thermometer and real-time clock integrates the critical functions of a real-time clock and a temperature sensor in a 150mil 8-pin SO package (DS1629S). Communication to the DS1629 is accomplished through a 2-wire interface. The wide power supply range and minimal power requirement of the DS1629 allow for accurate time/temperature measurements in battery-powered applications. The real-time clock/calendar provides seconds, minutes, hours, day, day of the week, date of the month, month, and year. The end of the month date is automatically adjusted for months with less than 31 days, including corrections for leap years. The real-time clock operates in either a 12- or 24-hour format with AM/PM indicator in 12-hour mode. The user-supplied crystal oscillator frequency is internally divided, as specified by device configuration. An open-drain oscillator output is provided that can be used as the clock input to a microcontroller.The thermometer offers ±2°C accuracy over a -10°C to +85°C range. Thermometer data is read out in 2's complement format with 9 bits of resolution. Higher resolution readings can be calculated using data from the DS1629 counter and slope accumulator registers.The open-drain alarm output of the DS1629 becomes active when either the measured temperature exceeds the programmed over-temperature limit (TH) or the current time reaches the programmed alarm setting. The user can configure which event (time only, temperature only, either, or neither) will generate an alarm condition. For storage of general system data or time/temperature datalogging, the DS1629 provides 32 bytes of SRAM.ApplicationsComputer ServersMedical Devices

The DS18B20 digital thermometer provides 9-bit to 12-bit Celsius temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20 communicates over a 1-Wire bus that by definition requires only one data line (and ground) for communication with a central microprocessor. In addition, the DS18B20 can derive power directly from the data line ('parasite power'), eliminating the need for an external power supply.Each DS18B20 has a unique 64-bit serial code, which allows multiple DS18B20s to function on the same 1-Wire bus. Thus, it is simple to use one microprocessor to control many DS18B20s distributed over a large area. Applications that can benefit from this feature include HVAC environmental controls, temperature monitoring systems inside buildings, equipment, or machinery, and process monitoring and control systems.How to Spatially Index 1-Wire® Sensors Using the MAXREFDES131 and DS18B20 FAQs: DS18B20ApplicationsConsumer ProductsIndustrial SystemsThermally Sensitive SystemsThermometersThermostatic Controls

The MAX6695/MAX6696 are precise, dual-remote, and local digital temperature sensors. They accurately measure the temperature of their own die and two remote diode-connected transistors, and report the temperature in digital form on a 2-wire serial interface. The remote diode is typically the emitter-base junction of a common-collector PNP on a CPU, FPGA, GPU, or ASIC.The 2-wire serial interface accepts standard system management bus (SMBus) commands such as Write Byte, Read Byte, Send Byte, and Receive Byte to read the temperature data and program the alarm thresholds and conversion rate. The MAX6695/MAX6696 can function autonomously with a programmable conversion rate, which allows control of supply current and temperature update rate to match system needs. For conversion rates of 2Hz or less, the temperature is represented as 10 bits + sign with a resolution of +0.125°C. When the conversion rate is 4Hz, output data is 7 bits + sign with a resolution of +1°C. The MAX6695/MAX6696 also include an SMBus timeout feature to enhance system reliability.Remote temperature sensing accuracy is ±1.5°C between +60°C and +100°C with no calibration needed. The MAX6695/MAX6696 measure temperatures from -40°C to +125°C. In addition to the SMBus active-low ALERT output, the MAX6695/MAX6696 feature two overtemperature limit indicators (active-low OT1 and active-low OT2), which are active only while the temperature is above the corresponding programmable temperature limits. The active-low OT1 and active-low OT2 outputs are typically used for fan control, clock throttling, or system shutdown.The MAX6695 has a fixed SMBus address. The MAX6696 has nine different pin-selectable SMBus addresses. The MAX6695 is available in a 10-pin µMAX® and the MAX6696 is available in a 16-pin QSOP package. Both operate throughout the -40°C to +125°C temperature range.ApplicationsDesktop ComputersNotebook ComputersServersTest and Measurement EquipmentWorkstations

The MAX6627/MAX6628 precise digital temperature sensors report 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. The MAX6627/MAX6628 can also measure the die temperature of other ICs, such as microprocessors (µPs) or microcontrollers (µCs) that contain an on-chip, diode-connected transistor.Remote accuracy is ±1°C when the temperature of the remote diode is between 0°C and +125°C and the temperature of the MAX6627/MAX6628 is +30°C. The temperature is converted to a 12-bit + sign word with 0.0625°C resolution. The architecture of the device is capable of interpreting data as high as +145°C from the remote sensor. The MAX6627/MAX6628 temperature should never exceed +125°C.These sensors are 3-wire serial interface SPI-compatible, allowing the MAX6627/MAX6628 to be readily connected to a variety of µCs. The MAX6627/MAX6628 are read-only devices, simplifying their use in systems where only temperature data is required.Two conversion rates are available, one that continuously converts data every 0.5s (MAX6627), and one that converts data every 8s (MAX6628). The slower version provides minimal power consumption under all operating conditions (30µA, typ). Either device can be read at any time and provide the data from the last conversion.Both devices operate with supply voltages between +3.0V and +5.5V, are specified between -55°C and +125°C, and come in space-saving 8-pin SOT23 and lead-free TDFN packages.ApplicationsHard Disk DriveIndustrial Control SystemsNotebooks, PCsSmart Battery Packs/Chargers

The MAX6660 is a remote temperature sensor and fan-speed regulator that provides a complete fan-control solution. The remote temperature sensor is typically a common-collector PNP, such as a substrate PNP of a microprocessor, or a diode-connected transistor, typically a low-cost, easily mounted 2N3904 NPN type or 2N3906 PNP type.The device also incorporates a closed-loop fan controller that regulates fan speed with tachometer feedback. The MAX6660 compares temperature data to a fan threshold temperature and gain setting, both programmed over the SMBus™ by the user. The result is automatic fan control that is proportional to the remote-junction temperature. The temperature feedback loop can be broken at any time for system control over the speed of the fan.Fan speed is voltage controlled as opposed to PWM controlled, greatly reducing acoustic noise and maximizing fan reliability. An on-chip power device drives fans rated up to 250mA.Temperature data is updated every 0.25s and is readable at any time over the SMBus interface. The MAX6660 is accurate to 1°C (max) when the remote junction is between +60°C to +100°C. Data is formatted as a 10-bit + sign word with 0.125°C resolution.The MAX6660 is specified for -40°C to +125°C and is available in a 16-pin QSOP package.ApplicationsIndustrial Control SystemsNotebook ComputersPCServersTelecom SystemsWorkstations