Targeting servers, storage equipment, and routers, Primarion’s PX4650 and PX4640 integrated power stages (iPSs) are presented as being the smallest available, measuring 4 mm × 6 mm. The 20-lead QFN-packaged chips combine low-RDS(ON) N-channel MOSFETs for high- and low-side FETs with high- and low-side MOSFET drivers. The RoHS-compliant units support an average output current of up to 50 A in 24 mm² per stage when combined with Primarion’s digital multiphase or Di-POL controllers. The iPSs exhibit efficiency from 92% to 94%, input undervoltage protection, average current limit protection when combined with a digital controller; integrated pulse-by-pulse peak current limit, and integrated overtemperature protection. The components offer a temperature monitor, switching frequency from 200 kHz to 1.3 MHz, and 3-state PWM input compatibility.