Analog temperature sensing with a linear 10mV/°C scale
The LM45BIM3/NOPB is an analog local temperature sensor from Texas Instruments that outputs a voltage directly proportional to temperature at 10mV/°C. This scaling means a reading of 250mV corresponds to 25°C, and 750mV corresponds to 75°C — no digital conversion or I²C bus required, just an ADC channel on the microcontroller. Accuracy is rated at ±2°C typical, with a worst-case ±3°C across the full -20°C to 100°C operating range. For a system that needs to stay within ±2°C of a setpoint, this sensor meets the requirement without calibration at the board level.
The device operates from a 4V to 10V supply, which covers common 5V and 9V rails. The output voltage at 100°C is 1.0V, well within the input range of a 3.3V ADC. No negative supply is needed — the sensor is single-supply and ground-referenced. Packaged in a three-pin SOT-23-3 (TO-236-3, SC-59), the footprint is compact enough for dense PCB layouts. The supply, ground, and output pins follow the standard pinout for this package family, making it a drop-in replacement for other SOT-23-3 analog temperature sensors with the same pin mapping.