A regulator circuit is presented. The regulation circuit (530) has a regulation switch (131), a voltage comparator (537) with predetermined offset voltage and an adjuster. The regulation switch (131) has a first terminal coupled to a current source (132), a second terminal connectable to a load (110), and a control terminal. The voltage comparator (537) compares a sum voltage of the offset voltage added to a voltage at the second terminal with a control voltage at the control terminal, and generates a comparison signal. The adjuster adjusts the voltage at the second terminal based on the comparison signal to control a difference voltage between the control terminal and the second terminal of the regulation switch and to maintain the regulation switch operating in a desired region of operation.