Patent ID: 8149014
Filing Date: 2012-04-03
Classification: H03K

Abstract:
1. A method for providing an I/O driver with v/i characteristic control for maintaining a substantially flat output impedance response using a configuration at an I/O output pad, the method comprising the acts of: providing a linear resistive element electrically connected at the I/O pad for limiting variations of a processed I/O signal; and providing an active impedance matching element for receiving and processing pull-up and pull-down array calibration words and a data signal comprising data represented by a series of voltage state transitions to generate and output the processed I/O output signal to the linear resistive element such that the I/O pad displays a substantially flat v/i response at switching of the data signal, the active impedance element further comprising a pull-up stage and a pull-down stage, wherein the pull-up stage comprises: wherein the pull-down stage comprises: providing a logical circuit for controlling the active impedance matching element for providing inputs to the pull-up array and the pull-up array, the inputs including the pull-up and pull-down array calibration words and inputs to the pull-up base circuit and to the pull-down base circuit; wherein during I/O operation, a combined impedance contribution from the linear resistive element and the active impedance matching element provides for the substantially flat output impedance.