TEMPERATURE SENSOR ROHS COMPLIANT: YES

Precision Thermocouple Amplifiers with Cold Junction Compensation

Thermostats SERIAL DIGITAL OUTPUT THERMOMETER

The AD22105 is a solid state thermostatic switch. Requiring only one external programming resistor, the AD22105 can be set to switch accurately at any temperature in the wide operating range of -40°C to +150°C. Using a novel circuit architecture, the AD22105 asserts an open collector output when the ambient temperature exceeds the user-programmed setpoint temperature. The AD22105 has approximately 4°C of hysteresis which prevents rapid thermal on/off cycling.The AD22105 is designed to operate on a single power supply voltage from +2.7 V to +7.0 V facilitating operation in battery powered applications as well as in industrial control systems. Because of low power dissipation (230 µW @ 3.3 V), self-heating errors are minimized and battery life is maximized.An optional internal 200 k(ohm) pull-up resistor is included to facilitate driving light loads such as CMOS inputs.Alternatively, a low power LED indicator may be driven directly. APPLICATIONS Industrial process control Thermal control systems CPU monitoring Computer thermal management circuits Fan control Handheld/portable electronic equipment

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 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 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 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

TEMPERATURE SENSOR;

TEMPERATURE SENSOR, -40 TO 150DEG C;