Sense amplifier system and sensing method thereof

A sense amplifier, comprising:

• a first switch having a first terminal receiving a power voltage, a second terminal, and a bulk terminal electrically connected to the first terminal;
• a second switch having a first terminal electrically connected to the second terminal of the first switch, and a bulk terminal;
• a third switch having a first terminal electrically connected to the first terminal of the second switch, and a bulk terminal electrically connected to the bulk terminal of the second switch;
• and
• a fourth switch having a first terminal electrically connected to the bulk terminal of the first switch and a second terminal electrically connected to the bulk terminal of the third switch.

A sensing method for a sense amplifier, the sense amplifier comprising two input devices for receiving two input signals, each input device having a bulk terminal, wherein the sense amplifier further comprises a first to a fourth switches, the second and the third switches are respectively the two input devices, each of the first to the third switches has a first, a second, a control and a bulk terminals, the fourth switch has a first, a second and a control terminals, the second terminal of the first switch is electrically connected to the first terminals of the second and the third switches, the bulk terminal of the first switch is electrically connected to the first terminal thereof, the control terminals of the second and the third switches respectively receive a reference and an input voltages being the two input signals, the bulk terminals of the second and the third switches are directly electrically connected to each other, the first terminal of the fourth switch is electrically connected to the bulk terminal of the first switch, and the second terminal of the fourth switch is electrically connected to the bulk terminal of the third switch, the method comprising:

• turning off the fourth switch when the second and the third switches are charged through the control terminals thereof such that the bulk terminals of the second and the third switches are floating during a sensing period;
• and
• comparing the reference voltage and the input voltage.