An integrated circuit comprises a gain stage circuit coupled to a compensation circuit. Both the gain stage circuit and the compensation circuit respectively comprise a first current source and a second current source that are subject to the same process variations. A negative feedback circuit is used to generate a corrective current in relation to the second current source, indicative of a current that needs to flow through a load in addition to a current flowing through the second current source in order for a variable voltage to be substantially equal to a reference voltage used to drive the first and second current sources. A compensating current corresponding to the corrective current generated for the second current source is applied to the first current source to compensate for process variation in the gain stage circuit in respect to the first current source.