Микроконтроллеры AVR

totem-pole это термин из логики TTL, где эта схема не совсем push-pull, как в усилителях, откуда этот термин и появился. Вот хорошее объяснение этого A push–pull output is a type of electronic circuit that can drive either a positive or a negative current into a load. Push–pull outputs are present in TTL and CMOS digital logic circuits and in some types of amplifier, and are usually realized as a complementary pair of transistors, one dissipating or sinking current from the load to ground or a negative power supply, and the other supplying or sourcing current to the load from a positive power supply. Because of the way these circuits are drawn schematically, with two transistors stacked vertically, they are sometimes called "totem pole" outputs( or circuits)