A semiconductor device includes a trim storage and an encoder. The trim storage stores trim values. The encoder determines a magnitude of a supply voltage, determines a magnitude of a handle voltage, determines a source-to-handle voltage of a first transistor, and determines a source-to-handle voltage of a second transistor. Further, the encoder determines a target number of selectable first transistor units comprising the first transistor to select for the first transistor. Based on a trim value from the trim storage, the source-to-handle voltage of the first transistor and the source-to-handle voltage of the second transistor, the encoder determines a target number of selectable second transistor units comprising the second transistor to select for the second transistor. The encoder asserts control signals to select the target number of selectable first transistor units and the target number of selectable second transistor units.