Thermostats Digital Thermometer and Memory

The TMP35/TMP36/TMP37 are low voltage, precision centigrade temperature sensors. They provide a voltage output that is linearly proportional to the Celsius (centigrade) temperature. The TMP35/ TMP36/TMP37 do not require any external calibration to provide typical accuracies of ±1°C at +25°C and ±2°C over the −40°C to +125°C temperature range.The low output impedance of the TMP35/TMP36/TMP37 and its linear output and precise calibration simplify interfacing to temperature control circuitry and ADCs. All three devices are intended for single-supply operation from 2.7 V to 5.5 V maximum. The supply current runs well below 50 μA, providing very low self-heating—less than 0.1°C in still air. In addition, a shutdown function is provided to cut the supply current to less than 0.5 μA.The TMP35 is functionally compatible with the LM35/LM45 and provides a 250 mV output at 25°C. The TMP35 reads temperatures from 10°C to 125°C. The TMP36 is specified from −40°C to +125°C, provides a 750 mV output at 25°C, and operates to 125°C from a single 2.7 V supply. The TMP36 is functionally compatible with the LM50. Both the TMP35 and TMP36 have an output scale factor of 10 mV/°C.The TMP37 is intended for applications over the range of 5°C to 100°C and provides an output scale factor of 20 mV/°C. The TMP37 provides a 500 mV output at 25°C. Operation extends to 150°C with reduced accuracy for all devices when operating from a 5 V supply.The TMP35/TMP36/TMP37 are available in low cost 3-lead TO-92, 8-lead SOIC_N, and 5-lead SOT-23 surface-mount packages.

SPI-/I2C-Compatible, 10-Bit Digital Temperature Sensor and 8-Channel ADC

10-Bit Digital Temperature Sensor (AD7416) and Four Single-Channel ADCs

Board Mount Temperature Sensors TEMP TRANSDUCER IC

AD590 - 2-Terminal IC Temperature Transducer

Features:

• Linear current output: 1 µA/K
• Wide temperature range: -55°C to +150°C
• Probe compatible ceramic sensor package
• 2-terminal device: voltage in/current out
• Laser trimmed to ±0.5°C calibration accuracy (AD590M)
• Excellent linearity: ±0.3°C over full range (AD590M)
• Wide power supply range: 4 V to 30 V
• Sensor isolation from case
• Available in 2-lead FLATPACK, 4-lead LFCSP, 3-pin TO-52, 8-lead SOIC, and die form

Additional Details:

The AD590 is a 2-terminal integrated circuit temperature sensor that generates an output current directly proportional to absolute temperature. With supply voltages ranging from 4 V to 30 V, it functions as a high-impedance, constant-current source, delivering 1 μA per Kelvin. The chip's thin-film resistors are laser-trimmed to ensure a precise output of 298.2 μA at 298.2 K (25°C).

The AD590 is ideal for temperature-sensing applications below 150°C, offering a cost-effective alternative to traditional electrical temperature sensors. Its monolithic design eliminates the need for additional support circuits like linearization, precision amplifiers, resistance measurement, or cold junction compensation.

Beyond temperature measurement, the AD590 is suitable for applications such as temperature compensation, biasing proportional to absolute temperature, flow rate measurement, fluid level detection, and anemometry. Available in die form, it is well-suited for hybrid circuits and rapid temperature measurement in protected environments.

The AD590 excels in remote sensing applications, thanks to its high-impedance current output, which minimizes the effect of voltage drops over long distances. A well-insulated twisted pair can transmit data over hundreds of feet to the receiving circuitry. Additionally, the AD590 is easy to multiplex, as its current can be switched using a CMOS multiplexer, or the supply voltage can be controlled by a logic gate output.

 

The AD590 is a 2-terminal integrated circuit temperature trans-ducer that produces an output current proportional to absolute temperature. For supply voltages between 4 V and 30 V, the device acts as a high impedance, constant current regulator passing 1 μA/K. Laser trimming of the chip’s thin-film resistors is used to calibrate the device to 298.2 μA output at 298.2 K (25°C).The AD590 should be used in any temperature-sensing application below 150°C in which conventional electrical temperature sensors are currently employed. The inherent low cost of a monolithic integrated circuit combined with the elimination of support circuitry makes the AD590 an attractive alternative for many temperature measurement situations. Linearization circuitry, precision voltage amplifiers, resistance measuring circuitry, and cold junction compensation are not needed in applying the AD590.In addition to temperature measurement, applications include temperature compensation or correction of discrete components, biasing proportional to absolute temperature, flow rate measurement, level detection of fluids and anemometry. The AD590 is available in die form, making it suitable for hybrid circuits and fast temperature measurements in protected environments.The AD590 is particularly useful in remote sensing applications. The device is insensitive to voltage drops over long lines due to its high impedance current output. Any well-insulated twisted pair is sufficient for operation at hundreds of feet from the receiving circuitry. The output characteristics also make the AD590 easy to multiplex: the current can be switched by a CMOS multiplexer, or the supply voltage can be switched by a logic gate output.PRODUCT HIGHLIGHTS The AD590 is a calibrated, 2-terminal temperature sensor requiring only a dc voltage supply (4 V to 30 V). Costly transmitters, filters, lead wire compensation, and linearization circuits are all unnecessary in applying the device. State-of-the-art laser trimming at the wafer level in conjunction with extensive final testing ensures that AD590 units are easily interchangeable. Superior interface rejection occurs because the output is a current rather than a voltage. In addition, power requirements are low (1.5 mW @ 5 V @ 25°C). These features make the AD590 easy to apply as a remote sensor. The high output impedance (>10 MΩ) provides excellent rejection of supply voltage drift. For instance, changing the power supply from 5 V to 10 V results in only a 1 μA maximum current change, or 1°C equivalent error. The AD590 is electrically durable: it withstands a forward voltage of up to 44 V and a reverse voltage of 20 V. Therefore, supply irregularities or pin reversal does not damage the device.

The TMP35/TMP36/TMP37 are low voltage, precision centigrade temperature sensors. They provide a voltage output that is linearly proportional to the Celsius (centigrade) temperature. The TMP35/ TMP36/TMP37 do not require any external calibration to provide typical accuracies of ±1°C at +25°C and ±2°C over the −40°C to +125°C temperature range.The low output impedance of the TMP35/TMP36/TMP37 and its linear output and precise calibration simplify interfacing to temperature control circuitry and ADCs. All three devices are intended for single-supply operation from 2.7 V to 5.5 V maximum. The supply current runs well below 50 μA, providing very low self-heating—less than 0.1°C in still air. In addition, a shutdown function is provided to cut the supply current to less than 0.5 μA.The TMP35 is functionally compatible with the LM35/LM45 and provides a 250 mV output at 25°C. The TMP35 reads temperatures from 10°C to 125°C. The TMP36 is specified from −40°C to +125°C, provides a 750 mV output at 25°C, and operates to 125°C from a single 2.7 V supply. The TMP36 is functionally compatible with the LM50. Both the TMP35 and TMP36 have an output scale factor of 10 mV/°C.The TMP37 is intended for applications over the range of 5°C to 100°C and provides an output scale factor of 20 mV/°C. The TMP37 provides a 500 mV output at 25°C. Operation extends to 150°C with reduced accuracy for all devices when operating from a 5 V supply.The TMP35/TMP36/TMP37 are available in low cost 3-lead TO-92, 8-lead SOIC_N, and 5-lead SOT-23 surface-mount packages.

The AD596/AD597 is a monolithic temperature setpoint controller which has been optimized for use at elevated temperatures such as those found in oven control applications. The device cold junction compensates and amplifies a type J or K thermocouple input to derive an internal signal proportional to temperature. The internal signal is then compared with an externally applied setpoint voltage to yield a low impedance switched output voltage. Dead-Band or switching hysteresis can be programmed using a single external resistor. Alternately, the AD596/ AD597 can be configured to provide a voltage output (10 mV/°C) directly from a type J or K thermocouple signal. It can also be used as a stand-alone voltage output temperature sensor.The AD596/AD597 can be powered with a single supply from +5 V to +30 V, or dual supplies up to a total span of 36 V. Typical quiescent supply current is 160 µA which minimizes self-heating errors.The AD596/AD597 H package option includes a thermocouple failure alarm that indicates an open thermocouple lead when operated in the temperature proportional measurement mode. The alarm output has a flexible format which can be used to drive relays, LEDs or TTL logic.The device is packaged in a reliability qualified, cost effective 10-pin metal can, 8-pin plastic mini-DIP or SOIC and is trimmed to operate over an ambient temperature range from +25°C to +100°C. Operation over an extended ambient temperature range is possible with slightly reduced accuracy. The AD596 will amplify thermocouple signals covering the entire -200°C to +760°C temperature range recommended for type J thermocouples while the AD597 can accommodate -200°C to +1250°C type K inputs.The AD596/AD597 has a calibration accuracy of ±4°C at an ambient temperature of 60°C and an ambient temperature stability specification of 0.05°C/°C from +25°C to +100°C. If higher accuracy, or a lower ambient operating temperature is required, either the AD594 (J thermocouple) or AD595 (K thermocouple) should be considered.

The AD7814 is a complete temperature monitoring system in aSOT-23 package or 8-lead MSOP package. It contains a bandgap temperature sensor and 10-bit ADC to monitor and digitizethe temperature reading to a resolution of 0.25°CThe AD7814 has a flexible serial interface that allows easy interfacing to most microcontrollers. The interface is compatiblewith SPI®, QSPI™, and MICROWIRE™ protocol, and is alsocompatible with DSPs. The part features a standby mode that iscontrolled via the serial interface.The AD7814’s wide supply voltage range, low supply current,and SPI-compatible interface make it ideal for a variety ofapplications, including personal computers, office equipment,and domestic appliances.PRODUCT HIGHLIGHTS The AD7814 has an on-chip temperature sensor that allows an accurate measurement of the ambient temperature. The measurable temperature range is –55°C to +125°C, with a ±2°C temperature accuracy. Supply voltage of 2.7 V to 5.5 V Space-saving 6-lead SOT-23 package and 8-lead MSOP package 10-bit temperature reading to 0.25°C resolution Standby mode that reduces the current consumption to 1 µAAPPLICATIONS Hard Disk Drives Personal Computers Electronic Test Equipment Office Equipment Domestic Appliances Process Control

The ADT74701 controller is a multichannel temperature sensor and PWM fan controller and fan speed monitor for systems requiring active cooling. It is designed to interface directly to an I2C® bus. The ADT7470 can monitor up to 10 daisy-chained TMP05 temperature sensors. It can also monitor and control the speed of four fans, in automatic or in manual control loops.A FULL_SPEED input is provided to allow the fans to be blasted to maximum speed, via external hardware control, under extreme thermal conditions or on system startup. An SMBALERT interrupt communicates error conditions such as fan under speed and over temperature measurements to the system service processor. Individual error conditions can then be read from status registers over the I2C bus.APPLICATIONS Servers Networking and telecommunications equipment Desktops