ZXCM210 ZETEX [Zetex Semiconductors], ZXCM210 Datasheet - Page 5

• Manufacturer Part Number: ZXCM210
• Description: VERY LOW POWER MICROPROCESSOR RESET DEVICES
• Manufacturer: ZETEX [Zetex Semiconductors]

APPLICATIONS INFORMATION
Negative going V
The ZXCM209/210 are, to a good degree, immune to
short duration negative going supply transients. Under
certain circumstances very brief transients are allowed
without inappropriate false triggering of the reset
circuit. The response to supply transients is shown in the
Noise Immunity graph in the typical characteristics. The
graph indicates the typical allowable transient duration
for a specified threshold overdrive such that a reset
pulse is not generated. Addition of a bypass capacitor,
e.g. 0.1µF, as close as possible to the V
extra transient immunity.
Figure 1
Circuit for operation of ZXCM with reset valid down to very low supply voltage.
ISSUE 3 - FEBRUARY 2001
v
cc
ZXCM209
Gnd
v
cc
Output
Reset
CC
transients
100k
Reset
Input
Micro
Gnd
v
cc
CC
pin will provide
5
Reset valid down to very low supply voltages
With V
ZXCM209/210 may be in an undefined state. In many
sy s t e ms
microprocessor, and other circuits, will be inoperative
with supplies this low. In applications where this is
important, the addition of an external resistor ensures
that the reset output remains valid for V
resistor value is non critical: a value of 100k
recommended. For the ZXCM209 the resistor should
be applied between reset output and ground: for the
ZXCM210 between reset output and V
shows the connection diagram for the ZXCM devices
in these configurations.
v
cc
CC
ZXCM210
between 0V and 1V the output of the
Gnd
v
t h i s
cc
Output
Reset
i s
100k
i n c o n se q u e n t i a l
Reset
Input
Micro
Gnd
v
cc
ZXCM209
ZXCM210
CC
CC
. Figure 1
< 1V. The
a s
t h e
is