adm809-5lartz-rl7 Analog Devices, Inc., adm809-5lartz-rl7 Datasheet - Page 8

• Manufacturer Part Number: adm809-5lartz-rl7
• Description: Microprocessor Supervisory Circuit In 3-lead Sc70, Active-low Open-drain Output
• Manufacturer: Analog Devices, Inc.

ADM803/ADM809/ADM810
INTERFACING TO OTHER DEVICES’ OUTPUT
The ADM803/ADM809/ADM810 series is designed to integrate
with as many devices as possible and, therefore, has a standard
output dependent on V
both 3 V and 5 V, or any nominal voltage within the minimum
and maximum specifications for V
interfacing the ADM803/ADM809/ADM810 to other devices.
ENSURING A VALID RESET OUTPUT DOWN TO
V
When V
longer sinks current. A high impedance CMOS logic input
connected to RESET may, therefore, drift to undetermined logic
levels. To eliminate this problem, a 100 kΩ resistor should be
connected from RESET to ground.
BENEFITS OF AN ACCURATE RESET THRESHOLD
In other microprocessors, tolerances in supply voltages lead
to an overall increase in reset tolerance levels due to the
deterioration of the reset circuit’s power supply. In the
ADM803/ADM809/ADM810, the possibility of a malfunction
during a power failure is greatly reduced because the devices
can operate effectively even when there are large degradations
of the supply voltages. Another advantage is the very accurate
internal voltage reference circuit of the ADM803/ADM809/
ADM810. These benefits combine to produce an exceptionally
reliable voltage monitor circuit.
CC
= 0 V
Figure 11. Ensuring a Valid Reset Output Down to V
CC
falls below 0.8 V, the ADM803/ADM809 RESET no
ADM809
CC
GND
V
V
CC
CC
. This enables the parts to be used in
RESET
CC
. This design simplifies
CC
= 0 V
Rev. G | Page 8 of 12
INTERFACING TO MICROPROCESSORS WITH
MULTIPLE INTERRUPTS
In a number of cases, it is necessary to interface many interrupts
from different devices (for example, thermal, altitude, and
velocity sensors). The ADM803/ADM809/ADM810 can easily
be integrated into existing interrupt-handling circuits, as shown
in Figure 12, or can be used as standalone devices.
Figure 12. Interfacing to Microprocessors with Multiple Interrupts
ADM809
GND
V
V
CC
CC
RESET
PRIORITY ENCODER
74LS147
OTHER SENSING
DEVICES
4-LINE BCD TO
MICROPROCESSOR