The PWM output encodes the measured temperature as a duty cycle, readable by any MCU timer input. This eliminates the need for an analog input pin or an external ADC, saving board area and cost. The output is a digital signal, so it is less susceptible to noise coupling on long traces compared to an analog voltage output. The PWM frequency and duty-cycle mapping are defined in the datasheet; the part does not require an external clock or filter.
The SC-70-5 (SOT-353) package is a 5-lead surface-mount footprint. It is small enough for dense layouts but still hand-solderable with care. The supplier device package is SC-70-5. Tape & Reel and Cut Tape options are available for prototyping and production.