1. TPS2061D Substitution Conclusion The TPS2061D cannot serve as a direct replacement for the AP2181SG-13. The key differences are as follows: First, the output type differs—the AP2181SG-13 is P-channel, whereas the TPS2061D is N-channel. This results in fundamentally different logic-level requirements for the enable (EN) signal (one active-high, the other active-low) and potentially different drive schemes referenced to ground. Direct substitution would prevent the switch from being controlled correctly. Second, the maximum output current differs: 1.5A for the AP2181SG-13 versus 1A for the TPS2061D, which introduces a risk of overload in applications with higher load current demands. Third, there is a lack of fault protection features—the TPS2061D lacks the reverse current protection present in the AP2181SG-13, a critical disadvantage in applications such as USB that require power path isolation. Substitution is not feasible unless the circuit design can accommodate a lower current margin, forego reverse current protection, and accept modifications to the drive logic and peripheral circuitry.