Enhanced Charge Pump Architecture with Feedback Supply Selector for Optimized Switching Performance

Conventional operational amplifier designs often experience parameter performance issues during the transition between complementary input differential stages, which restricts the full rail-to-rail common mode voltage swing. This paper presents an innovative charge pump architecture featuring a feedback supply selector that optimizes the transition performance. The proposed approach employs a switched-capacitor technique to boost the supply voltage by 1.5 V relative to the input voltage, thereby enabling the use of a single pMOS differential input stage. The novel supply selector dynamically chooses the maximum available voltage between the external supply and the boosted output, ensuring efficient transistor switching and improved biasing. Schematic-level and post-layout simulations in a 250 nm CMOS process validate the design under varied load currents, supply voltages, temperatures, and process corners. Results show a significant reduction in output voltage ripple, with a maximum value of 48 mV achieved post-layout, and enhanced overall efficiency, even under higher load currents. This architecture provides a robust and scalable solution for advanced operational amplifiers, particularly in fields where high performance and stability are critical.