Focusing now on the ON/OFF timer columns, these values show how long a push button must be pressed before the enable output is asserted/deasserted. The fifth column, the Kill timer, describes how long the system microprocessor is given before the push button controller automatically releases the enable output. As you can see, certain timers are fixed or adjustable, depending on the part. The LTC2950 and LTC2951 offer basic push button functionality in a tiny 3 mm x 2 mm DFN or SOT-23 package. The LTC2952 provides ideal diode power paths and system monitoring functionality. The LTC2953 offers system monitoring, undervoltage lockout and microprocessor interrupt functionality. Lastly, the LTC2954 offers the push button function with a microprocessor interrupt.