Techniques pertaining to a circuit architecture capable of controlling a current source to a predefined precision are disclosed. According to one aspect of the present invention, an automatic trimming circuit is proposed to automatically trim a current generated from a current generator or circuit in accordance with a reference current. The automatic trimming circuit includes a comparator, an ADC and a register. The comparator that may be implemented as a subtractor finds a difference between a generated current and a reference current. The difference is then digitized to an n-bit precision. A digital representation of the difference is then kept in a register and used subsequently correct or modify the generated current to produce a precisely controlled current.