Patent attributes
A configuration circuit for obtaining a digital code includes a controller circuit that generates a plurality of multibit control words. A digitally controlled current source circuit receives a multibit control word generated by the controller circuit. The digitally controlled current source circuit generates an output current that corresponds to the multibit control word in accordance with a predetermined output curve. A test voltage node receives the output current, and a test voltage develops in response to the output current. A reference voltage node develops a reference voltage, the level of which is independent of the multibit control word. A voltage comparison circuit (i) receives the test voltage and the reference voltage, (ii) compares the two voltages to produce a comparison result and (iii) sends the comparison result to the controller circuit. The digital code is obtained by the configuration circuit using the comparison result and the multibit control word.