Of Abbreviations - Philips DVDR880/001 Service Manual

EN 182 9. DVDR880-890 /0X1
OPERATING DESCRIPTION
The NCP300 and NCP301 series devices are second
generation ultra–low current voltage detectors. Figures 21
and 22 show a timing diagram and a typical application.
Initially consider that input voltage V
and it is greater than the voltage detector upper threshold
(V ), and the reset output (Pin 1) will be in the high state
DET+
for active low devices, or in the low state for active high
devices. If there is a power interruption and V
significantly deficient, it will fall below the lower detector
threshold (V ). This sequence of events causes the Reset
DET–
output to be in the low state for active low devices, or in the
Reset Output (Active Low), Pin 1
Reset Output (Active High), Pin 1
Circuit-, IC Descriptions and List of Abbreviations
NCP300, NCP301
is at a nominal level
in
becomes
in
V
in
Input Voltage, Pin 2
V +
DET
V
DET–
V
in
V +
DET
V
DET–
0 V
V
in
V +
DET
V
DET–
0 V
Figure 21. Timing Waveforms
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high state for active high devices. After completion of the
power interruption, V will again return to its nominal level
in
and become greater than the V
has built–in hysteresis to prevent erratic reset operation as
the comparator threshold is crossed.
Although these device series are specifically designed for
use as reset controllers in portable microprocessor based
systems, they offer a cost–effective solution in numerous
applications where precise voltage monitoring is required.
Figure 22 through Figure 29 shows various application
examples.
17
. The voltage detector
DET+