The invention provides a
bridge circuit and a
switching power supply, the
bridge circuit comprises at least one bridge arm and at least one anti-
crosstalk circuit, the bridge arm comprises two driving switching tubes connected in series, the anti-
crosstalk circuit comprises a
negation circuit and a clamping switching tube, a first end of the driving switching tube is connected with a controller and a first end of the clamping switching tube, and a second end of the driving switching tube is connected with a second end of the
negation circuit. The second end of the driving switch tube is connected with the second end of the clamping switch tube, and the second end of the driving switch tube is connected with the negative
electrode of the
diode in the driving switch tube. The first end of the driving switch tube and the
negation circuit are used for receiving a driving
signal sent by the controller, and the negation circuit is used for negating the driving
signal and sending the negated driving
signal to the third end of the clamping switch tube, so that the clamping switch tube is kept on when the driving switch tube is turned off. By adopting the
bridge circuit, the two ends of the driving switch tube can be clamped in time to absorb
crosstalk, the crosstalk
elimination effect is good, and the working reliability of the switch tube in the bridge circuit is improved.