Funtional block diagram
The STTS75 is a high-precision digital CMOS temperature sensor IC with a sigma-delta temperature-to-digital converter and an I
2C-compatible serial digital interface. It is targeted for general applications such as personal computers, system thermal management, electronics equipment and industrial controllers. With best-in-class power-saving features and a small package,
it is ideal for handheld devices such as mobile phones and PDAs.
The STTS75 has two package options:
industry-standard 8-lead MSOP/TSSOP, and SO.
The device contains a band-gap temperature sensor and programmable 9- to 12-bit ADC, which monitors and digitizes the temperature to a resolution up to 0.0625 °C. The part is accurate to +3 °C over the full temperature measurement range of -55 °C to 125 °C, with +2 °C accuracy in the -25 °C to +100 °C range.
The STTS75 is specified to operate at supply voltages from 2.7 V to 5.5 V. Operating at 3.3 V, the supply current is typically 75 µA.
The on-board sigma-delta analog-to-digital converter (ADC) converts the measured temperature to a digital value that is calibrated in degrees Celsius; for Fahrenheit applications, a lookup table or conversion routine is required.
The STTS75 is factory-calibrated and requires no external components to measure temperature. The power-up defaults permit standalone operation as a thermostat. A dual-purpose event pin operates as an interrupt or comparator/thermostat output. The power-saving one-shot mode can be used when the part is in shutdown to perform a single temperature conversion.
The STTS75 has a simple 2-wire I2C-compatible digital serial interface which allows the user to access the data in the temperature register at any time. It communicates via the serial interface with a master controller which operates at speeds up to 400 kHz. Three pins (A0, A1 and A2) are available for address selection, and enable the user to connect up to 8 devices on the same bus without address conflict. In addition, the serial interface gives the user easy access to all STTS75 registers to customize operation of the device.
