1. AP2161SG-13 Substitution Conclusion This part is a viable direct replacement in terms of core voltage compatibility and package pinout, but exhibits critical performance differences. The primary changes involve an optimization of the switch type from "General Purpose" to "USB Switch," and a shift from an N-channel to a P-channel output structure. It integrates an internal charge pump, enabling control of the high-side P-MOSFET with a single logic-level signal, thereby simplifying the design. Its maximum output current is increased to 1A, significantly higher than the original part's 200mA, offering greater drive capability. However, the typical on-resistance rises to 95mOhm (compared to the original 33mOhm). Consequently, under the same load current, the conduction voltage drop and power dissipation will increase notably, potentially impacting efficiency and thermal performance. Additionally, it introduces "Reverse Current Blocking" protection, making it more suitable for applications like USB ports where backflow prevention is required. Substitution is feasible if the application's current demand is well below 1A, is not sensitive to switch conduction losses, and benefits from the enhanced protection features. If the original design operates near its 200mA full-load rating, careful evaluation of thermal rise is necessary.