The multi-channel shimming coils have been proposed to improve the magnetic field homogeneity locally. The one-coil-one-driver solution is preferred to keep the high flexibility. The linear-mode and switch-mode solutions are feasible for such low current applications. However, the switch-mode current driver has the advantage of smaller size in space-limited situations, such as for coils with high number elements. Here we present the design and implementation of a single H-bridge shimming driver. The performance comparison of analog controller and digital controller is shown, and also two different pulse width modulation methods.