Temperature Sensor: Serial Digital Output Thermometers CMOS/TTL Comp.

The TMP03/TMP04 are monolithic temperature detectors that generate a modulated serial digital output that varies in direct proportion to the temperature of the device. An onboard sensor generates a voltage precisely proportional to absolute temperature which is compared to an internal voltage reference and input to a precision digital modulator. The ratiometric encoding format of the serial digital output is independent of the clock drift errors common to most serial modulation techniques such as voltage-to-frequency converters. Overall accuracy is ±1.5°C (typical) from –25°C to +100°C, with excellent transducer linearity. The digital output of the TMP04 is CMOS/TTL compatible, and is easily interfaced to the serial inputs of most popular microprocessors. The open-collector output of the TMP03 is capable of sinking 5 mA. The TMP03 is best suited for systems requiring isolated circuits utilizing optocouplers or isolation transformers.

The TMP03 and TMP04 are specified for operation at supply voltages from 4.5 V to 7 V. Operating from 5 V, supply current (unloaded) is less than 1.3 mA.

The TMP03/TMP04 are rated for operation over the –40°C to +100°C temperature range in the low cost TO-92, SO-8, and TSSOP-8 surface mount packages. Operation extends to 150°C with reduced accuracy.

Applications

* Isolated sensors

* Environmental control systems

* Computer thermal monitoring

* Thermal protection

* Industrial process control

* Power system monitors

* Low cost 3-pin package

* Modulated serial digital output

* Proportional to temperature

* ±1.5°C accuracy (typ) from –25°C to +100°C

* Specified –40°C to +100°C, operation to 150°C

* Power consumption 6.5 mW max at 5 V

* CMOS/TTL-compatible output

* Low voltage operation (4.5 V to 7 V)