1. Substitution Conclusion for LP3962EMP-2.5/NOPB From the perspective of core electrical specifications and package, the LP3962 can essentially achieve a pin-for-pin direct replacement. However, there are clear degradations in its key performance parameters. Firstly, its quiescent current (9 mA) is significantly higher than that of the original LP3872 (5 mA). Under light-load or standby conditions, the LP3962 will exhibit higher self-consumption, leading to reduced overall system efficiency. Secondly, its datasheet does not provide Power Supply Rejection Ratio (PSRR) data, whereas the LP3872 explicitly specifies an excellent 73dB to 57dB. The absence of this critical information makes the LP3962's performance in suppressing input supply ripple and noise unclear and likely inferior to the original part. For applications sensitive to efficiency or with stringent requirements for supply purity (e.g., precision analog circuits, RF modules), this substitution is not recommended. If intended solely for powering digital circuits where cost and quiescent current are not critical concerns, and the input supply is relatively clean, it could serve as a cost-reduction alternative. However, empirical testing is mandatory to verify that the output noise meets the application's requirements.