Some embodiments relate to a device for generating stimulation signals, comprising: a stimulation delivery circuit； a first component to monitor charge delivered in at least one charge pulse via the stimulation delivery circuit； and a second component to ensure delivered charge substantially corresponds to charge of a charge pulse intended to be delivered by the stimulation delivery circuit. In some embodiments, the device may further comprise a charge setting circuit responsive to a charge pulse setting signal, such as a constant current of fixed pulse width, to set the charge of the charge pulse intended to be delivered.
