Original Part
Alternative Part
1. TPS2021DG4 Substitution Conclusion
Feasible, with attention to logic level compatibility. The TPS2021DG4 is highly consistent with the original TPS2031DG4 in core specifications, including load voltage range, maximum output current, typical on-resistance, protection features, and package. The sole critical difference lies in the input logic type: the original part features a "non-inverting" (active-high) enable, whereas the TPS2021DG4 is "inverting" (active-low). In a direct replacement, the microcontroller's control signal logic must be inverted; otherwise, the switch's on/off states will be opposite to the design intent. With the corresponding adjustment made in firmware or via a front-end logic circuit, the TPS2021DG4 is a fully suitable substitute in terms of electrical performance and functionality.
2. AP2191SG-13 Substitution Conclusion
Direct substitution is not recommended due to fundamental differences. Although the AP2191SG-13 shares similarities with the original part in load voltage range, interface type, and some protection features, its core switching element has changed from an N-channel to a P-channel MOSFET, resulting in a different internal drive architecture. Furthermore, its typical on-resistance (95mΩ) is significantly higher than the original's (33mΩ), leading to greater voltage drop and heat dissipation under identical load current. While its rated maximum output current (1.5A) is higher, the practical power dissipation advantage is limited by the higher Rds(on). Additionally, while it is optimized as a "USB switch" and adds "reverse current protection," the underlying architectural differences mean it is not a pin-for-pin or performance-equivalent replacement for the original N-channel design. Direct substitution could adversely affect system efficiency and thermal performance.
Analysis ID: F80C-108F000
Based on part parameters and for reference only. Not to be used for procurement or production.
SkyChip © 2026, Email: sales@skychip.com