Patent ID: 7109785

Claim:
A current source for generating a constant reference current, comprising: an amplifier circuit which outputs a negative feedback voltage present across a first resistor in inverted amplified fashion as an amplifier output voltage; a first voltage/current converter which generates a current in a manner dependent on the amplifier output voltage; a first current mirror circuit which mirrors the current generated by the voltage/current converter to form, a mirrored current which flows through the first resistor in order to generate the negative feedback voltage, wherein the first current mirror circuit includes a first MOSFET; and a second current mirror circuit which mirrors the current generated by the voltage/current converter to form the reference current. wherein the first voltage/current converter includes a MOSFET having a gate connected to an output of the amplifier circuit, a source terminal connected to a negative supply voltage of the current source via a second resistor, and a drain terminal connected to a drain terminal of the first MOSFET of the first current mirror circuit; and wherein the resistance of the second resistor is adjustable.