To enable micro sleeps of transmitters during network inactivity without forfeiting real-time capabilities, power amplifiers (PAs) with fast operating point switching (OPS) are required. In this paper, for the first time to the authors’ best knowledge, OPS is investigated for efficient watt-level power amplifiers and measured turn-on times are reported. Based on a compact bias switching network suitable for GaN amplifiers, two new PAs, one in class E and one in class AB, with saturated output power around 40 dBm and ultra-fast OPS capability are presented. Turn-on times below 37 ns are achieved and idle power less than 1 mW is measured, enabling even microsecond sleeps with minimal latency for significant energy savings.