We report the tunable mid-infrared generation with a periodically poled LiNbO3 (PPLN). Using an all-solid-statepumped Nd: YVO4 laser as the pump source and a PPLN nonlinear crystal with grating periods of 28.2-30.8 μm,we have achieved wavelength conversion in the 2.90-4.05 μm spectral range by period tuning. The use of confocal cavity design has brought a compact, all-solid-state configuration with an average output powers of idler up to ～ 200 mW. The maximum power of 277mW was obtained at the wavelength of 3.35μm.