Browse Prior Art Database

CMOS Feedback Driver

IP.com Disclosure Number: IPCOM000116495D
Original Publication Date: 1995-Sep-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 69K

Publishing Venue

IBM

Related People

Cao, T: AUTHOR [+4]

Abstract

The modern microprocessor system design has placed an increased demand for better performance on the OFF-CHIP-DRIVER to meet the faster cycle times.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

CMOS Feedback Driver

      The modern microprocessor system design has placed an increased
demand for better performance on the OFF-CHIP-DRIVER to meet the
faster cycle times.

      The ordinary performance increase that comes from better more
advanced semiconductor processes have not been able meet this demand.

      Also limits have been reached with solution that simply
increase the circuit area to get better performance.

      A conventional off-chip driver circuit schematic is shown in
Fig. 1 .  More than one "ENABLE" is found along with a Data-in line.
The schematic shown in Fig. 1 serves as a reference for the new
invention shown in Fig. 2.

      Fig. 2 shows the new circuit.  The difference here is that the
output signal is fedback thru an inverter circuit consisting of
transistors QP6 & QN6.  The output of this inverter is then used as
input to an a second pair of inverters where the first of which is
provided by transistors QP4 & QN4 and the second of which is
constructed by transistors QP3 & QN3.  The outputs of the second pair
of inverters is then connected to the existing internal nodes of the
driver circuit at the gates of the output push-pull complimentary
transistor pair QP5 & QN5.  The feedback signal so connected is
out-of-phase with the incoming signal at this point ( the gates of
QN5 & QP5 ).

      Feedback techniques have been used for years to achieve
improved bandwidth in amplifiers and the OFF-CHIP-DRIVER can be
thought of as a form of a...