10 mV/°C scaling — what it means for the ADC input
The LM35CAZ/NOPB outputs an analog voltage that scales linearly at 10 mV per degree Celsius. At 25°C the output sits at 250 mV; at 100°C it reads 1.0 V. This direct mV-to-°C relationship means no external scaling resistors or linearization lookup table — the ADC sees a voltage that is numerically the temperature in tenths of a degree. That ±1°C band is the guaranteed limit for production test; the typical part runs tighter, but the BOM budget should use the ±1°C figure for worst-case system error analysis.
Supply range and output drive
The sensor operates from a 4 V to 30 V supply, drawing less than 60 µA quiescent current. The output is a low-impedance voltage source that can drive 1 mA into a load, so it feeds directly into a microcontroller ADC input or a comparator without a buffer. Because the output is an analog voltage referenced to ground, the ADC reference voltage sets the measurement resolution. With a 10-bit ADC on a 5 V reference, each count represents roughly 0.5°C; a 12-bit ADC on a 2.5 V reference gives about 0.06°C per count. The sensor's own noise floor is below 0.2°C peak-to-peak at 25°C, so the ADC resolution is the limiting factor in most designs.
TO-92 package — board-fit and thermal coupling
The LM35CAZ/NOPB comes in a standard TO-92-3 through-hole package (TO-226AA). The three leads are ground, output, and supply — the plastic body sits above the board, so the sensor measures ambient air temperature, not PCB copper temperature. For surface temperature measurement, the flat face of the TO-92 should be bonded to the target surface with a dab of thermal epoxy; the plastic body alone has poor thermal conductivity to the die. Self-heating is minimal — at 25°C with still air, the junction temperature rise above ambient is about 0.08°C. In forced airflow the rise drops further. This makes the TO-92 version suitable for duct air temperature sensing or enclosure ambient monitoring where the sensor is not touching a hot surface.