Body bias circuit and body bias generation method

A body bias circuit configured to generate a body bias for biasing a body terminal of a metal oxide semiconductor (MOS) switch, wherein the body bias circuit comprises:

• a first intrinsic MOS device, having the same conductivity type as the MOS switch and having an intrinsic threshold voltage;
• and
• an operational regulation circuit, coupled to the first intrinsic MOS device and configured to generate the body bias according to a first voltage at a first terminal of the MOS switch and the intrinsic threshold voltage;
• wherein the body bias is lower than the first voltage and a second voltage of a second terminal of the MOS switch;
• and
• wherein the operational regulation circuit generates the body bias, so that an on-resistance of the MOS switch is lower than a preset on-resistance threshold when the MOS switch is in a conduction operation, and/or a leakage current of the MOS switch is lower than a preset leakage current threshold when the MOS switch is in a non-conduction operation;
• wherein the body bias is the first voltage minus an offset voltage;
• wherein a threshold voltage of the MOS switch reversely tracks the intrinsic threshold voltage, and the offset voltage is negatively related to the intrinsic threshold voltage, so that the body bias is positively related to the intrinsic threshold voltage.