Improved Performance CMOS Off-Chip Driver
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
A complementary metal-oxide semiconductor (CMOS) off-chip driver (OCD) circuit has been designed with improved turn-on and turn-off characteristics, resulting in reduced power dissipation. In the featured design illustrated, a P-channel device (T15) drives a series of resistors (R180-R188) to control di/dt during turn- on of pull-down devices (T180-T188) while T160-T168 drive the gates directly to turn off the pull-down devices quickly and reduce the overlapping conductance of the pull-up and pull-down. Although the conductance of T170-T176 during pull-down is not as much a concern, T14 could similarly be decomposed into a set of separate devices, like T160-T168, which would be connected to internal nodes of the resistor chain R170-R176 for quicker turn-off of T170-T176.