1. TPS2021DR Substitution Conclusion The TPS2021DR is identical to the original TPS2031DRG4 in key parameters such as package, maximum current, on-resistance, and protection features. However, its critical distinction lies in the input logic: it is inverting, whereas the original part is non-inverting. In the same hardware circuit, a direct substitution would invert the switch control logic—i.e., where the original device turns on with a high-level signal, the TPS2021DR requires a low-level signal to turn on. This would likely prevent the system from properly controlling the load. Therefore, unless the circuit or control signal can be adapted to accommodate this logic inversion, direct replacement is not feasible.