2. AP2191SG-13 Substitution Conclusion The AP2191SG-13 is similar to the original part in terms of load voltage range, basic interface, and package. However, several fundamental technical differences exist, making it a less feasible direct substitute and necessitating a system-level re-evaluation. The key differences include: First, its output type is P-Channel, unlike the original N-Channel. This typically requires different gate drive voltage logic and may lead to incompatibility with the existing drive circuit. Second, its on-resistance (95mΩ) is significantly higher than the original part's (33mΩ), resulting in higher conduction losses and temperature rise under the same load current. Third, while its nominal current capability (1.5A) is higher, this comes at the cost of the increased on-resistance. Furthermore, it is specified as a "USB Switch," indicating its internal optimization and characteristics are likely tailored for USB power delivery scenarios, which may lead to different performance in general-purpose applications. Fourth, it incorporates an additional "Reverse Current Protection" feature, which is an added advantage. Substitution requires a thorough re-evaluation of power dissipation, thermal design, and drive circuit compatibility.