NOVELTY - The integrated buck-boost converter (10) has first and second switches, each having first and second terminals, first and second diodes having anodes and cathodes, an inductor (110), and a capacitor (112). The first and second switches are controlled to provide step-up and step-down operations. The first terminal of first switch (102) and the anode of first diode (106) form a two-port input side for receiving input voltage. The first and second terminals of the capacitor form two-port output side for outputting output voltage to charge a rechargeable battery (20).    USE - Integrated buck-boost converter of charging apparatus for charging rechargeable battery used in electric vehicle or electric motorcycle.    ADVANTAGE - Accurately provides required voltage level of the output voltage for charging the rechargeable battery since the integrated buck-boost converter provides both step-up operation and step-down operation by controlling the first and second switches. Efficiently reduces switching losses, and increases conversion efficiency.    DETAILED DESCRIPTION - The cathode of the first diode is electrically connected to the second terminal of the first switch. The first terminal of the inductor is electrically connected to the second terminal of the first switch and the cathode of the first diode. The anode of the second diode (108) is electrically connected to the second terminal of the inductor and the anode of the first diode. The first terminal of the capacitor is electrically connected to the cathode of the second diode, and the second terminal of the capacitor is electrically connected to the second terminal of the second switch (104) and the anode of the first diode.    DESCRIPTION OF DRAWING(S) - The drawing shows the circuit diagram of the integrated buck-boost converter of charging apparatus.    Integrated buck-boost converter (10)    Rechargeable battery (20)    First switch (102)    Second switch (104)    First diode (106)    Second diode (108)    Inductor (110)    Capacitor (112)