H6061 EMMICRO [EM Microelectronic - MARIN SA], H6061 Datasheet - Page 6

• Manufacturer Part Number: H6061
• Description: 3 V Self Recovering Watchdog
• Manufacturer: EMMICRO [EM Microelectronic - MARIN SA]

Typical Applications
Microprocessor Watchdog with Voltage Monitor
Selection of Watchdogs for Each Application
The H6061 is designed for monitoring regulated DC
voltages anywhere between 2.7 and 5.25 V. Typically, it is
used to monitor V
voltage divider (see Fig. 8). This arrangement has the
advantage of being able to trigger at selectable voltage
limits, i. e. it can be used where the regulated voltage is
below 5 VDC.
Industrial Heavy-Duty Utilisation
The H6061 debounce protects against reactions due to fast-
rise power lines, but absolute maximum ratings must be
respected. With its flexibility of voltage programming and
supply voltage the H6061 can allow for voltage drops along
supply lines, so it can be placed remotely, like on plug-in
boards (see Fig. 9). The H6061 is suitable for supply
voltages down to 2.7 VDC. As the H6061 is designed to be
sensitive to voltage changes, fast switching lines, like
address/data bus lines should not be run between the V
and V
shielding. Tracks from components to pin RC must be kept
very short. Pin RC if left free should be shielded with a
ground ring in noisy environments.
Copyright © 2004, EM Microelectronic-Marin SA
SS
supply lines near the H6061 without ground-plane
R
DD
with pin V
IN
tied to the midpoint of a
DD
6
The H6061 has only 40 mV hysteresis specially for
monitoring regulated DC. Pin V
any significant mains ripple or RFI (see Fig. 10). It should be
placed as near as possible to the point where voltage is to
be monitored. Pin V
(nominal 15 kΩ) against voltages in excess of V
environments this may however pick up enough mains
ripple or RFI to distort the voltage detection thresholds or
even cause unwanted sporadic resets in the absence of
adequate shielding or filtering on V
The H6061 has sufficient immunity to ripple and interference
on the V
meet severe criteria for injected spikes and RFI, then care
must be taken also decouple V
system protection must continue even under these
conditions. With normal series voltage regulators, the
regulated 5 VDC output voltage follows the DC rough
voltage within 1.5 V on powering up. If the application has
pin V
on-chip comparators will not rise above V
correctly programmed. With switched-mode power supplies
however, the DC-rough voltage on power-up rises almost to
its working level before the 5 VDC line starts to ramp up.
The H6061 has been specially designed to work under
these extreme conditions but care must be taken not to
exceed absolute maximum ratings. In addition to the voltage
monitoring on pin V
H6061 monitoring its own V
malfunction causes V
V
IN
stays high, then all outputs go active at once.
IN
monitoring the DC rough, the internal inputs to the
DD
supply line, but if it is important that a system
IN
DD
IN
, a final protection is given by the
is protected by an internal resistor
to fall below V
DD
IN
DD
www.emmicroelectronic.com
IN
from these influences, as
must be protected from
.
supply. If a system
OFF
DD
H6061
even though pin
if the H6061 is
DD
. In some