Patent ID: 7072415

Claim:
A system comprising: a. a multi-PAM output driver having a plurality of current-control ports; b. a current-calibration circuit coupled to each of the current-control ports, the current-calibration circuit including a first, second, and third reference-voltage nodes; and c. a multi-level voltage generator including: i. a voltage divider having first, second, third, and fourth resistors coupled in series to divide a reference voltage into a first multi-PAM reference voltage between the first and second resistors and coupled to the first reference-voltage node, a second multi-PAM reference voltage between the second and third resistors and coupled to the second reference-voltage node, and a third multi-PAM reference voltage between the third and fourth resistors and coupled to the third reference-voltage node; and ii. an active current source having a current-handling terminal and a current-control terminal, wherein the current-handling terminal is coupled between two of the first, second, third, and fourth resistors.