Method for providing a current of high accuracy

摘要

The current source uses an additional transistor to provide precise control of current about nominal value. The current is provided by a first transistor (T3) through which the first current passes. An operational amplifier (A2) has a first input to which a reference voltage (Vref) is applied, and at the output of which is a signal for controlling the first transistor. An external resistance (Re1) is also connected to the second input. A further transistor (T4) is provided through which a second current passes (I4), passing also through the external resistor.