The DS18B20-PAR digital thermometer provides 9 to 12-bit centigrade temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20-PAR does not need an external power supply because it derives power directly from the data line ('parasite power'). The DS18B20-PAR communicates over a 1-Wire® bus, which by definition requires only one data line (and ground) for communication with a central microprocessor. It has an operating temperature range of -55°C to +100°C and is accurate to ±0.5°C over a range of -10°C to +85°C.Each DS18B20-PAR has a unique 64-bit identification code, which allows multiple DS18B20-PARs to function on the same 1-wire bus; thus, it is simple to use one microprocessor to control many DS18B20-PARs 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.ApplicationsRemote Sensing Applications

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 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.ApplicationsDesktop ComputersGraphic CardsNotebook ComputersServersTest and Measurement EquipmentThin ClientsWorkstations

The LM75 temperature sensor includes a delta-sigma analog-to-digital converter, and a digital overtemperature detector. The host can query the LM75 through itsI²C interface to read temperature at any time. The open-drain overtemperature output (OS) sinks current when the programmable temperature limit is exceeded. The OS output operates in either of two modes, comparatoror interrupt. The host controls the temperature at which the alarm is asserted (TOS) and the hysteresis temperature below which the alarm condition is not valid (THYST). Also, the LM75's TOS and THYST registers can be read by the host. The address of the LM75 is set with three pins to allow multiple devices to work on the same bus. Power-up is in comparator mode, with defaults of TOS = +80°C and THYST = +75°C. The 3.0V to 5.5V supply voltage range, low supply current, and I²C interface make the LM75 ideal for many applications in thermal management and protection.ApplicationsComputers and Office ElectronicsTest EquipmentThermal ProtectionThermal System Management

The MAX6639 monitors its own temperature and one external diode-connected transistor or the temperatures of two external diode-connected transistors, typically available in CPUs, FPGAs, or GPUs. 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 program the alarm thresholds. Temperature data can be read at any time over the SMBus, and three programmable alarm outputs can be used to generate interrupts, throttle signals, or overtemperature shutdown signals.The temperature data is also used by the internal dual-PWM fan-speed controller to adjust the speed of up to two cooling fans, thereby minimizing noise when the system is running cool, but providing maximum cooling when power dissipation increases. Speed control is accomplished by tachometer feedback from the fan, so that the speed of the fan is controlled, not just the PWM duty cycle. Accuracy of speed measurement is ±4%.The MAX6639 is available in 16-pin QSOP and 16-pin thin QFN 5mm x 5mm packages. It operates from 3.0V to 3.6V and consumes just 500µA of supply current.ApplicationsDesktop ComputersNetworking EquipmentNotebook ComputersProjectorsServers

The MAX7500–MAX7504 temperature sensors accurately measure temperature and provide an overtemperature alarm/interrupt/shutdown output. These devices convert the temperature measurements to digital form using a high-resolution, sigma-delta, analog-to-digital converter (ADC). Communication is through an I²C-compatible 2-wire serial interface. The MAX7500/MAX7501/MAX7502 integrate a timeout feature that offers protection against I²C bus lockups. The MAX7503/MAX7504 do not include the timeout feature.The 2-wire 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 open-drain overtemperature shutdown output.The MAX7500 features three address select lines, while the MAX7501–MAX7504 feature two address select lines and an active-low RESET input. The MAX7500/MAX7501/MAX7502s' 3.0V to 5.5V supply voltage range, low250µA supply current, and a lockup-protected I²C-compatible interface make them ideal for a wide range of applications, including personal computers (PCs), electronic test equipment, and office electronics.The MAX7500–MAX7504 are available in 8-pin µMAX® and SO packages and operate over the -55°C to +125°C temperature range.ApplicationsElectronic Test EquipmentIndustrial Process ControlOffice ElectronicsPCsServers

The MAX7500–MAX7504 temperature sensors accurately measure temperature and provide an overtemperature alarm/interrupt/shutdown output. These devices convert the temperature measurements to digital form using a high-resolution, sigma-delta, analog-to-digital converter (ADC). Communication is through an I²C-compatible 2-wire serial interface. The MAX7500/MAX7501/MAX7502 integrate a timeout feature that offers protection against I²C bus lockups. The MAX7503/MAX7504 do not include the timeout feature.The 2-wire 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 open-drain overtemperature shutdown output.The MAX7500 features three address select lines, while the MAX7501–MAX7504 feature two address select lines and an active-low RESET input. The MAX7500/MAX7501/MAX7502s' 3.0V to 5.5V supply voltage range, low250µA supply current, and a lockup-protected I²C-compatible interface make them ideal for a wide range of applications, including personal computers (PCs), electronic test equipment, and office electronics.The MAX7500–MAX7504 are available in 8-pin µMAX® and SO packages and operate over the -55°C to +125°C temperature range.ApplicationsElectronic Test EquipmentIndustrial Process ControlOffice ElectronicsPCsServers

The DS1825 digital thermometer provides 9 to 12-bit centigrade temperature measurements and has an alarmfunction with NV user-programmable upper and lower trigger points. The DS1825 communicates over a 1-Wire® busthat by definition requires only one data line (and ground) for communication with a central microprocessor. It hasan operating temperature range of -55°C to +125°C and is accurate to ±0.5°C over the range of -10°C to +85°C. Inaddition, the DS1825 can derive power directly from the data line (“parasite power”), eliminating the need for anexternal power supply.Each DS1825 has a unique 64-bit serial code, which allows multiple DS1825s to function on the same 1-Wire bus;thus, it is simple to use one microprocessor to control many DS1825s distributed over a large area. In addition, the4-bit location address can be used to identify specific temperature sensors in the system without requiring a widelookup table. Applications that can benefit from this feature include HVAC environmental controls, temperaturemonitoring systems inside buildings, equipment or machinery, and process monitoring and control systems.ApplicationsConsumer ProductsIndustrial SystemsThermally Sensitive SystemsThermometersThermostatic Controls

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 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