1. TPS2031DR Substitution Conclusion The TPS2031DR can serve as a direct replacement, but with a critical caveat. The core difference lies in its input logic being "non-inverting," whereas the original TPS2021DR features an "inverting" input. Consequently, their response to the same control signal (e.g., from an MCU GPIO) is completely opposite: if the original design uses active-high control, the replacement will require active-low, and vice versa. Beyond this input logic polarity, the two devices are identical in electrical parameters, package, and protection features. The feasibility of substitution depends entirely on whether your circuit can accommodate or be modified for the inverted control logic. If hardware or software configuration cannot be altered, direct replacement will result in incorrect switch states. If the control logic can be adjusted accordingly, it can be considered a fully functional substitute.