1. XC6221A25A7R-G Substitution Conclusion From the perspective of key electrical parameters, package, and functionality, the XC6221A25A7R-G can serve as a drop-in replacement for the original XC6217C25A7R-G. Both devices are identical in output voltage, maximum input voltage, output current, dropout voltage, PSRR, enable control, and overcurrent protection, with fully compatible physical footprints. The key difference lies in the quiescent current (Iq): the original part specifies 8 µA, while the XC6221A variant draws 50 µA. This implies a significant increase in power dissipation (approximately 6x) under light-load or standby conditions for the substitute, which could substantially reduce battery runtime in portable devices. Consequently, this substitution is not viable in applications where ultra-low power consumption is critical. However, in continuously operating systems or designs where Iq is not a primary concern, the replacement is acceptable.