STCN75 Datasheet, PDF (6/35 Pages) STMicroelectronics – Digital temperature sensor and thermal watchdog

Summary description
1
Summary description
STCN75
The STCN75 is a high-precision digital CMOS temperature sensor IC with a sigma-delta
temperature-to-digital converter and an I²C-compatible serial digital interface (see Figure 1
on page 7). It is targeted for general applications such as personal computers, system
thermal management, electronics equipment, and industrial controllers, and is packaged in
the industry standard 8-lead TSSOP and SO8N packages.
The device contains a band gap temperature sensor and 9-bit ADC which monitor and
digitize the temperature to a resolution up to 0.5°C. The STCN75 is typically accurate to
(±3°C - max) 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 STCN75 is pin-for-pin and software compatible
with the TCN75.
STCN75 is specified for operating at supply voltages from 2.7V to 5.5V. Operating at 3.3V,
the supply current is typically (125µA).
The on-board sigma-delta analog-to-digital converter (ADC) converts the measured
temperature to a digital value that is calibrated in degrees Centigrade; for Fahrenheit
applications a lookup table or conversion routine is required.
The STCN75 is factory-calibrated and requires no external components to measure
temperature.
1.1
Serial communications
The STCN75 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 400kHz. 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 STCN75 registers to
customize operation of the device.
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