Patent Number: 6,297,677

Title: Method for a dynamic termination logic driver with improved slew rate control

Abstract: A dynamic termination logic driver, one that is capable of launching signals at a driving end of a transmission line and is capable of terminating signals at a receiver end of the transmission line, controls output impedance and includes within the driver an impedance circuit and slew rate control. Accordingly, a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance. The driver includes a pull up circuit coupled to receive at least one of a plurality of control codes and the driver also includes a pull down circuit coupled to receive at least one of the plurality of control codes. The output impedance of the driver is further controlled during transitional phases of tuning on and turning off the pull down circuit and the pull up circuit under a plurality of process, voltage and temperature (PVT) conditions.

Inventors: Ang; Michael A. (San Francisco, CA), Taylor; Alexander D. (Olga, WA), Starr; Jonathan E. (Cupertino, CA), Vishwanthaiah; Sai V. (Sunnyvale, CA)

Assignee: Sun Microsystems, Inc.

International Classification: H03K 19/003 (20060101); H03K 005/12 ()

Expiration Date: 10/02/2018