1. LP3855EMP-2.5/NOPB Substitution Conclusion The LP3855EMP-2.5/NOPB can directly replace the LP3872EMP-2.5/NOPB, representing a performance upgrade. Both devices share identical core specifications: a fixed 2.5V output, 1.5A current rating, 7V maximum input voltage, SOT-223-5 package, and enable control and protection features. This ensures full pin-to-pin hardware compatibility and functional equivalence. The key differences lie in the LP3855's superior performance parameters. Its maximum dropout voltage is reduced from 0.55V to 0.44V (both at 1.5A), allowing for lower input voltage under heavy loads. This improves power conversion efficiency and reduces power dissipation. The quiescent current is lowered from 5mA to 3mA, decreasing the IC's own power consumption—particularly beneficial for battery-powered applications or designs sensitive to standby power. Furthermore, the maximum supply current is reduced from 15mA to 10mA, reflecting optimized internal circuit power draw. Collectively, these improvements mean that substituting with the LP3855 yields lower total system power consumption, higher operational efficiency, and potentially a wider operating input voltage range—all without modifying any peripheral circuitry or PCB layout. Therefore, the substitution is not only feasible but results in a net positive gain in overall system performance.