Browse Prior Art Database

Programmable Variable Pulse Width And Frequency Pulse Generator

IP.com Disclosure Number: IPCOM000107721D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Nahata, P: AUTHOR

Abstract

Described is a programmable variable pulse-width frequency pulse generator circuit that provides a means of generating variable duty cycle pulses.

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This is the abbreviated version, containing approximately 55% of the total text.

Programmable Variable Pulse Width And Frequency Pulse Generator

       Described is a programmable variable pulse-width
frequency pulse generator circuit that provides a means of generating
variable duty cycle pulses.

      In certain electronic applications which utilize system clock
circuitry, it is necessary to divide the clock frequency by a number
other than a multiple of two.  Also, the ON time and the OFF time of
the clock frequency pulse is often required to be controlled by a
number other than two.

      In prior art, microprocessors have been incorporated to count
the pulses and to provide the output pulse at the applicable time.
However, this approach suffers from a disadvantage that while the
microprocessor is performing the pulse-counting function, it is not
available for other processing work.

      The concept described herein provides a means whereby the pulse
width and duty cycle can be variable.  Also, the design incorporates
a programmable feature without increasing the logic complexity.  The
circuit design, as shown in Fig. 1, utilizes two magnitude
comparators X and Y. Magnitude comparator X controls the output pulse
OFF time, and magnitude comparator Y controls the ON time of the
output pulse.  The comparators function as a multiple of the system
clock frequency.

      The inputs to the comparators are connected to a mechanical
device, such as a thumbwheel switch, which provides the required ON
and OFF time information.  T...