What this sensor does on your board
The TMP112AIDRLR is a digital local temperature sensor that reads the temperature of its own die and reports it over an I²C or SMBus interface. It resolves temperature to 12 bits, giving you 0.0625°C per LSB, and hits ±0.5°C typical accuracy over the -20°C to 65°C range — the part of the curve most designs care about. Supply voltage runs from 1.4V to 3.6V, so it works straight off a 1.8V or 3.3V rail without a separate LDO. The full operating temperature span is -40°C to 125°C, covering industrial and automotive ambient requirements.
It comes in a SOT-563 or SOT-666 package, with the supplier device package listed as SOT-5X3 — a six-lead package about 1.6 mm × 1.6 mm. Surface-mount only, so it goes through reflow with the rest of the board. The small footprint means you can place it close to the heat source you are measuring — near a power inductor, a processor, or a battery cell — without eating board area. No external components needed beyond a pull-up resistor on the I²C lines.
Power-saving features for battery gear
One-Shot mode lets the sensor take a single measurement and then go back to sleep, drawing minimal current between reads. Shutdown Mode drops the supply current even further, useful for devices that only check temperature once a minute. The Output Switch feature lets you connect the ALERT pin to an interrupt line on the MCU, so the processor only wakes up when the temperature crosses a threshold.
The base product number is TMP112, so the whole family is current.