The LM339AM/NOPB is a quad single supply comparator from Texas Instruments. It features open-collector outputs, a wide operating supply voltage range, low input bias current, and high-speed response time. It is ideal for use in temperature sensing, as well as in industrial, automotive, and consumer applications. It is offered in the tiny SOT-23-6 package and comes with no-power-down protection, so it won't drift out of the spectrum during a power go-down.