The present invention discloses a bus pumping compensation for a pulse modulation circuit such as class D modulators. The compensation according to the present invention provides a compensation current controlled by the output voltage, with the compensation characteristics matching the reverse current for improving circuit efficiency. Embodiments of the present invention also disclose a designable compensation circuit, comprising a linear compensation current, offering a good trade-off between circuit efficiency and ease of design. The present invention compensation circuit is preferably employed in a class D amplifier with substantial reverse current, and most preferably added into a LDO power supply in a class D amplifier circuit to prevent reverse current problem. The disclosed class D amplifier circuit is preferably used in an audio media player.