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Noise Sense Circuit

IP.com Disclosure Number: IPCOM000105679D
Original Publication Date: 1993-Aug-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Klink, E: AUTHOR [+4]

Abstract

Described is a noise sense circuit which is not influenced by a low cut-off frequency, coupling disturbances and other factors. Also described is a circuit for measuring the noise pulse width.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 74% of the total text.

Noise Sense Circuit

      Described is a noise sense circuit which is not influenced by a
low cut-off frequency, coupling disturbances and other factors.  Also
described is a circuit for measuring the noise pulse width.

      Fig. 1 shows the Basic Digital Noise Sense Circuit BDNSC.
Depending upon the setting of the reference voltage, either the power
or the ground noise sensitivity is measured.  Assuming the reference
voltage is slightly below the threshold voltage (case a in Fig. 1),
then both CMOS devices of the standard circuit with hysteresis are
ON.  The P-channel device, which is turned on more strongly, pulls
output 01 and thus output 02 to up level.  A power noise pulse in
case a turns the P- channel device slightly off, and the N-channel
device pulls output 01 to down level for a short time.  This AC pulse
at output 01 is then trans formed into a digital H-0-H pulse of
output 02.  The ground noise is transformed in a similar manner into
a digital 0-H-0 pulse, if the reference voltage is slightly above the
threshold value and the N- channel device is turned on more strongly
(case b Fig. 1).

      The BDNSC output 02 is also used as an A-clock input (Fig. 2)
for a series of seven master slave latches.  They are set to a steady
mode by the pull-down resistor connected to the data input and are
latched with the aid of the master/slave clock.  In addition, the
first latch stores a "1".  When the reference voltage is set and a
power/ground noise s...