Patent Number: 7,355,453

Title: Techniques for trimming drive current in output drivers

Abstract: Techniques are provided for trimming drive current in output drivers to compensate for process variations, model inaccuracies, and/or an off-target process. The actual output drive current is measured on the integrated circuit (IC) at wafer sort or during a final test. Based on the measured output drive current, the total transistor width that is required in the output driver to meet an I/O standard is calculated. A control block controls trimming transistors that are coupled in parallel with main output drive transistors. The control block adjusts the total width of the output drive transistors to bring the total width as close as possible to the desired width. Each I/O driver on a die can be adjusted individually based on its own drive current characteristics. All I/O drivers on a die can be adjusted by the same transistor width based on a single I/O measurement or on multiple I/O measurements.

Inventors: Watt; Jeffrey (Palo Alto, CA)

Assignee: Altera Corporation

International Classification: H03K 19/094 (20060101)

Expiration Date: 2020-04-08 0:00:00