Patent ID: 7015846

Claim:
A constant current source with threshold voltage and channel length modulation, comprising: a set of cascade transistors including a first MOS transistor and a second MOS transistor; and a compensation circuit electrically connected to the first MOS transistor and the second MOS transistor so as to form a feedback circuit, the compensation circuit comprising: a third MOS transistor whose gate terminal is connected to a gate terminal of the second MOS transistor; a fourth MOS transistor connected to the third MOS transistor in serial and having a gate terminal, a first terminal and a second terminal, wherein the gate terminal of the fourth MOS transistor is connected to a gate terminal of the first MOS transistor, and the second terminal of the fourth MOS transistor is connected to a current-supplying circuit; and a fifth MOS transistor and a sixth MOS transistor, wherein the gate terminals of the fifth and sixth MOS transistors are electrically connected to the current-supplying circuit, and current is generated by mirroring flows through the third MOS transistor.