The LTK001 is a thermocouple amplifier supplied with a matched cold junction compensator. By separating the amplifier and compensator functions, the problem of compensator temperature rise is virtually eliminated. The compensator is a selected version of the LT1025 cold junction compensator. The amplifier, which is also available separately as LTKA0x has been specially selected for thermocouple applications. It has low supply current to minimize warmup drift, very low offset voltage (<35µV), high gain, and extremely low input bias currents (<600pA) to allow high impedance input filters to be used without degrading offset voltage or drift.Matching of the kits is accomplished by separating the compensators and amplifiers according to the polarity of their initial (room temperature) errors. This eliminates the need to sum the errors of the two components to find the worst-case error.The LTK001 has direct thermocouple outputs of 60.9µV/°C (E), 51.7µV/°C (J), 40.6µV/°C (K, T), and 5.95µV/°C (R, S). It also has a 10mV/°C output which can be scaled to match any arbitrary thermocouple.For multiple thermocouple applications using one compensator, amplifiers may be ordered separately (LTKA0x), still matched to the compensator.Applications Thermocouple Cold Junction Compensation

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 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 DS1631, DS1631A, and DS1731 digital thermometers provide 9, 10, 11, or 12-bit temperature readings over a -55°C to +125°C range. The DS1631 and DS1631A thermometer accuracy is ±0.5°C from 0°C to +70°C with 3.0V ≤ VDD ≤ 5.5V, and the DS1731 accuracy is ±1°C from -10°C to +85°C with 3.0V ≤ VDD ≤ 5.5V. The thermostat on all three devices provides custom hysteresis with user-defined trip points (TH and TL). The TH and TL registers and thermometer configuration settings are stored in NV EEPROM so they can be programmed prior to installation. In addition, the DS1631A automatically begins taking temperature measurements at power-up, which allows it to function as a stand-alone thermostat.ApplicationsMedicalNetworkingPersonal ComputingRouters/SwitchesTest Measurement SystemsWireless Base Stations

The DS1631, DS1631A, and DS1731 digital thermometers provide 9, 10, 11, or 12-bit temperature readings over a -55°C to +125°C range. The DS1631 and DS1631A thermometer accuracy is ±0.5°C from 0°C to +70°C with 3.0V ≤ VDD ≤ 5.5V, and the DS1731 accuracy is ±1°C from -10°C to +85°C with 3.0V ≤ VDD ≤ 5.5V. The thermostat on all three devices provides custom hysteresis with user-defined trip points (TH and TL). The TH and TL registers and thermometer configuration settings are stored in NV EEPROM so they can be programmed prior to installation. In addition, the DS1631A automatically begins taking temperature measurements at power-up, which allows it to function as a stand-alone thermostat.ApplicationsMedicalNetworkingPersonal ComputingRouters/SwitchesTest Measurement SystemsWireless Base Stations

The DS1631, DS1631A, and DS1731 digital thermometers provide 9, 10, 11, or 12-bit temperature readings over a -55°C to +125°C range. The DS1631 and DS1631A thermometer accuracy is ±0.5°C from 0°C to +70°C with 3.0V ≤ VDD ≤ 5.5V, and the DS1731 accuracy is ±1°C from -10°C to +85°C with 3.0V ≤ VDD ≤ 5.5V. The thermostat on all three devices provides custom hysteresis with user-defined trip points (TH and TL). The TH and TL registers and thermometer configuration settings are stored in NV EEPROM so they can be programmed prior to installation. In addition, the DS1631A automatically begins taking temperature measurements at power-up, which allows it to function as a stand-alone thermostat.ApplicationsMedicalNetworkingPersonal ComputingRouters/SwitchesTest Measurement SystemsWireless Base Stations

The DS1775 digital thermometer and thermostatprovides temperature readings that indicate the device’stemperature. Thermostat settings and temperaturereadings are all communicated to/from the DS1775 overa simple 2-wire serial interface. No additional componentsare required; the device is truly a “temperature-to-digital”converter.For applications that require greater temperature resolution,the user can adjust the readout resolution from 9 to 12bits. This is particularly useful in applications wherethermal runaway conditions must be detected quickly.The open-drain thermal alarm output, O.S., becomesactive when the temperature of the device exceeds auser-defined temperature TOS. The number of consecutivefaults required to set O.S. active is configurable by theuser. The device can also be configured in the interrupt orcomparator mode, to customize the method which clearsthe fault condition.As a digital thermometer, the DS1775 is software compatiblewith the DS75 2-wire thermal watchdog. The DS1775 isassembled in a compact 5-pin SOT23 package, allowingfor low-cost thermal monitoring/control in spaceconstrainedapplications. The low thermal mass allows fortime constants previously only possible with thermistors.ApplicationsAny Thermally-Sensitive SystemCell PhonesOffice EquipmentPersonal Computers/Servers/Workstations

The DS1822-PAR is a digital thermometer with ±2°C accuracy over a -10°C to +85°C range and an operating temperature range of -55°C to +100°C. Data is read out over a 1-Wire® serial bus in 2's complement format with 9 to 12 bits of resolution (user-programmable).The DS1822-PAR is a parasite-power only version of the DS1822 that is ideal for use in remote-sensing applications such as temperature probes. Parasite power eliminates the need for a local power supply since power is derived directly from the 1-Wire bus. The DS1822-PAR provides mechanical simplicity over the DS1822 for parasite-power applications because no VDD connection is required—the DS1822 must have VDD connected to ground for operation in parasite-power mode.The DS1822-PAR offers thermostatic functionality with user-programmable over-temperature (TH) and under-temperature (TL) set points stored in on-chip EEPROM. Each DS1822-PAR features a unique and unchangeable 64-bit silicon serial number, which serves as the bus address for the sensor. This allows multiple DS1822-PAR devices to coexist on the same 1-Wire bus.The DS1822-PAR is offered a 3-pin TO-92 package. Also available is the high-precision DS18B20-PAR, which provides ±0.5°C accuracy and is software-compatible with the DS1822-PAR.ApplicationsRemote Sensing Applications

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