Patent ID: 7432730
Filing Date: 2008-10-07
Classification: H03K

Abstract:
1. A process for controlling slew rate of a driver, comprising: establishing a time reference for target driver output transition time; measuring driver output transition time; comparing the measured transition time to the time reference; and compensating the driver based on an error signal proportional to a difference between the measured transition time and the time reference by adjusting the driver output transition time to the time reference, whereby the driver output transition time corresponds to an output transition rate of a prior stage; adjusting a driver slew rate by controlling current through the prior stage with a current limited inverter scheme that includes two current sources; converting, with respective charge pumps, two digital error signals resulting from the comparing of the measured transition time to the time reference into two analog signals; and biasing each of the two current sources with a respective one of the two analog signals, wherein each respective charge pumps is arranged for each edge measurement.