Patent ID: 7382308

Claim:
A reference buffer comprising: a first current mirror formed by a first transistor and a second transistor, the first transistor driven by a first current generated by a constant current source and the second transistor driven by a second current proportional to the first current; a second current mirror formed by the first transistor and a third transistor, the third transistor driven by a third current proportional to the first current; a first source follower coupled in series to the second transistor and receiving a first initial reference voltage and outputting a first reference voltage; a second source follower coupled in series to the third transistor and receiving a second initial reference voltage and outputting a second reference voltage; and a first resistor coupled between a first node and a second node, the first node disposed between the second transistor and the first source follower and the second node disposed between the third transistor and the second source follower, and wherein: a voltage difference between the first reference voltage and the first initial reference voltage is substantially same as the voltage difference between the second reference voltage and the second initial reference voltage.