Patent ID: 7696909

Claim:
An apparatus comprising: a plurality of position adjustment units wherein each position adjustment unit includes: a current mirror; a set of transistors wherein each transistor from the set of transistors is coupled to the current mirror at its control electrode; and a first set of switches wherein each switch from the first set of switches is coupled between at least one of the transistors from the set of transistors and an output node; a first slope adjustment unit having a first digital-to-analog converter (DAC) with a second set of switches, wherein the first slope adjustment unit includes: a current source that generates a current that is proportional to absolute temperature; a first switch that is coupled to at least one of the position adjustment units; a second switch that is coupled to at least one of the position adjustment units; a third switch that is coupled to at least one of the position adjustment units; a fourth switch that is coupled to at least one of the position adjustment units; a fifth switch that is coupled to at least one of the position adjustment units; a first NMOS transistor that is diode connected and that is coupled to the current source at its drain; a second NMOS transistor that is coupled to the gate of the first NMOS transistor at its gate and that is coupled to the first switch at its drain; a third NMOS transistor that is coupled to the gate of the first NMOS transistor at its gate and that is coupled to the second switch at its drain; a fourth NMOS transistor that is coupled to the gate of the first NMOS transistor at its gate and that is coupled to the third switch at its drain; a fifth NMOS transistor that is coupled to the gate of the first NMOS transistor at its gate and that is coupled to the fourth switch at its drain; and a sixth NMOS transistor that is coupled to the gate of the first NMOS transistor at its gate and that is coupled to the fifth switch at its drain; and a second slope adjustment unit having a second DAC with a third set of switches wherein each switch from the third set of switches is coupled to the output node.