1. XC6221C2727R-G Substitution Conclusion The XC6221C2727R-G is fully compatible with the original XC6501C2717R-G in key parameters including package, output voltage (2.7V), maximum input voltage (6V), and output current (200mA), providing a hardware foundation for direct substitution. Differences include: the quiescent current (Iq) increases from 20μA to 50μA, which slightly raises power consumption under light-load or standby conditions and may affect battery-operated device runtime; the nominal dropout voltage is significantly lower (original: 0.38V@200mA, new: 0.17V@100mA—note differing test conditions, though actual full-load dropout likely remains comparable or better), improving efficiency in low-input-voltage scenarios; and PSRR improves from 50dB to 70dB, indicating substantially enhanced power supply ripple rejection, making it more suitable for noise-sensitive applications. Overall, if the application can tolerate a modest increase in quiescent current, this part can replace the original with equal or better performance and compatibility, particularly excelling in high-noise environments or where low dropout is critical.