Original Part
Linear Voltage Regulator IC Positive Fixed 1 Output 1.5A SOT-223-5
Alternative Part
Linear Voltage Regulator IC Positive Fixed 1 Output 1.5A SOT-223-5
Linear Voltage Regulator IC Positive Fixed 1 Output 1.5A SOT-223-5
1. LP3855EMP-2.5/NOPB Substitution Conclusion
The LP3855 is a viable substitute. It maintains full compatibility with the original LP3962 in core functionality, pinout, input/output voltage and current capability, enable control, and protection features. However, its key performance parameters are significantly optimized: it offers a lower dropout voltage (0.44V vs. 0.55V @1.5A), resulting in reduced power dissipation and lower device temperature under the same load, and allowing operation from a lower input voltage. The quiescent current is also lower (3mA vs. 9mA), directly improving efficiency under light-load or standby conditions. Furthermore, the LP3855 provides a clearly specified PSRR of 73dB @120Hz—a parameter not documented for the original part—ensuring well-defined suppression of input supply ripple and delivering a cleaner voltage to the load. Substitution with the LP3855 may yield improvements in system efficiency, thermal management, and noise rejection.
2. LP3872EMP-2.5/NOPB Substitution Conclusion
The LP3872 is a suitable replacement. It matches the original LP3962 in package, electrical specifications (input/output voltage, maximum output current), control, and protection functions, providing a direct functional drop-in. The differences are as follows: its quiescent current falls between the two parts (5mA vs. the original 9mA), offering better standby power consumption than the original but slightly higher than the LP3855. Like the LP3855, it provides a clearly specified PSRR of 73dB @120Hz, addressing the lack of documented noise rejection performance in the original part. The LP3872 is an equivalent substitute with comparable performance and guaranteed key specifications (PSRR). Its use introduces no performance risk and provides quantifiable confidence in power supply noise rejection after replacement.
Analysis ID: BCA7-52EF000
Based on part parameters and for reference only. Not to be used for procurement or production.
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