The present disclosure provides a medical device that includes a neurostimulator. The neurostimulator includes one or more channels. Each channel includes a digitally-controlled switch coupled to a voltage source. The switch is in one of an “on” state and an “off” state in response to a first control signal. Each channel also includes a digitally-controlled current sink coupled to the switch. The current sink is coupled between the switch and the voltage source. The current sink draws a variable amount of electrical current in response to a second control signal. Each channel further includes a conductor coupled to the switch and the current sink. The conductor is configured to be coupled to an electrode that is operable to deliver the electrical current drawn by the current sink to a target tissue area.