Signal sampling system and single-phase PFC converter

The invention belongs to the field of power electronics, and particularly relates to a signal sampling system and a single-phase PFC converter. The input voltage sampling module comprises an alternating current zero line lead ACN and an alternating current live wire lead ACL; the input end of the first differential amplification circuit is connected with an alternating current zero line lead ACN and an alternating current live wire lead ACL, and the output end of the first differential amplification circuit is connected with an INB + pin and an INB-pin of the first chip IC1, and is used for acquiring a voltage signal and performing differential processing on the voltage signal; the first chip IC and the second chip IC are connected through the first filter circuit, the OUTB pin of the first chip IC is connected with the INA + pin and the INA-pin of the first IC1 through the first filter circuit, filtering, following and control are carried out on voltage signals after differential processing, common-mode inte