ST Microelectronics has released a new series of precision digital-output temperature sensors, operating over the -55 to +125 degrees C temperature range, which are suitable for low power applications in a wide range of product areas.
The STxx75 devices are software-compatible drop-in replacements for industry standard LM75, DS75 and TCN75A parts, and also complement ST Microelectronics STLM20 analog temperature sensor.
The digital sensors, in standard 8-lead TSSOP and SO-8 packages, are used in control application where a processor with an I2C bus/SMBus needs to take action based on an accurate digital reading of the local temperature, or where an alarm or interrupt is required when a preset temperature level is reached.
They use a band-gap temperature sensor, with a programmable 9-bit to 12-bit sigma-delta ADC (analog to digital converter) to digitise the temperature reading to a resolution of up to 0.0625 degrees C.
The STTS75 devices are factory-calibrated and require no external components.
Accuracy is plus or minus 3 degrees over the full -55 to +125 degrees C temperature range, and plus or minus 2 degrees from -25 to +100 degrees C.
The STTS75 series are designed for a supply voltage range of 2.7V to 5.5V and have a low operating current of 75uA (typical) at 3.3V.
In the power saving shutdown mode the standby current is a very low 1uA maximum. Power-up defaults enable standalone operation as a thermostat, and both temperature and hysteresis values are programmable.
Typical applications include any product with a hard drive including laptops, servers and some set-top boxes plus medical equipment, industrial controllers and LCD backlighting.
Brighter displays and higher speed circuits mean more heat is being generated, which must be dissipated in ever-smaller packages.
This challenge for thermal management in consumer and industrial electronics means that the temperature of ICs and ambient air must be carefully monitored to prevent over-heating and damage.
The STTS75 series is available in volume in SO-8 and MSOP8 (TSSOP8) packages.