This work presents a hybrid buck converter with improved heavy-and-light load efficiency and enhanced power (current) density. The proposed converter uses outphase-interleaved switched-capacitor (OISC) cells to relieve the flying capacitor ($C_{\mathrm{F}}$) inrush current under extreme duty-ratios (D). It can also operate without an output capacitor ($C_{\mathrm{O}\mathrm{U}\mathrm{T}}$), improving the overall form factor. Besides, the intrinsic topological property realizes inductor-current recycling, which boosts the light-load efficiency without discontinuous-conduction mode (DCM) control. We also propose a self-hold gate driving scheme using a shared charge pump to eliminate the off-chip bootstrapping capacitors ($C_{\mathrm{B}\mathrm{S}\mathrm{T}}$). Fabricated in 180-nm BCD, the prototype supports a wide-range load current ($I_{\mathrm{L}\mathrm{O}\mathrm{A}\mathrm{D}}$) of 0.05-3.1A and converts a 1.8-3.3V input to a 0.8-1.8V output with a peak efficiency of 97.3%, and a peak current density of 585mA/mm³. With zero $C_{\mathrm{O}\mathrm{U}\mathrm{T}}$, the measured output ripple is below 60mV at 1.8$V_{\mathrm{O}\mathrm{U}\mathrm{T}}$ and 3. 1A$I_{\mathrm{L}\mathrm{O}\mathrm{A}\mathrm{D}}$.