Apparatus are disclosed, such as those involving a transmitter circuit that is configured to generate multi-level signals based on a plurality of data digits. One such transmitter circuit includes a signal output and an encoder configured to provide control signals based at least partially on the plurality of data digits. The transmitter circuit also includes a first set of switches configured to receive one or more of the control signals, and to selectively conduct a first or second voltage reference to the signal output. The transmitter circuit further includes first and second voltage drop circuits that provide third and fourth voltage references, respectively. The third and fourth voltage references have voltage levels between those of the first and second voltage references. The transmitter circuit also includes a second set of switches configured to receive one or more of the control signals, and selectively conduct the third or fourth voltage reference to the signal output.