ADM809-5LART-REEL Analog Devices Inc, ADM809-5LART-REEL Datasheet - Page 7

• Manufacturer Part Number: ADM809-5LART-REEL
• Description: IC SUPERVISOR MPU 4.63V SOT23
• Manufacturer: Analog Devices Inc
• Type: Simple Reset/Power-On Resetr

Specifications of ADM809-5LART-REEL

• Rohs Status: RoHS non-compliant
• Number Of Voltages Monitored: 1
• Output: Push-Pull, Totem Pole
• Reset: Active Low
• Reset Timeout: 140 ms Minimum
• Voltage - Threshold: 4.63V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-3, TO-236-3, Micro3™, SSD3, SST3

THEORY OF OPERATION
INTERFACING TO OUTPUT OF OTHER DEVICES
The ADM809-5L/ADM809-5S are designed to integrate with as
many devices as possible and, therefore, have an output dependent
on V
to other devices is simplified.
ENSURING A VALID RESET OUTPUT DOWN TO
V
When V
RESET no 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 A VERY ACCURATE RESET THRESHOLD
In other microprocessor supervisory circuits, tolerances in supply
voltages lead to an overall increase in RESET tolerance levels
due to the deterioration of the RESET circuit power supply of
the microprocessor. The possibility of a malfunction during
a power failure is greatly reduced because the ADM809-5L/
ADM809-5S can operate effectively even when there are large
degradations of the supply voltages. Another advantage of the
ADM809-5L/ADM809-5S series is its very accurate internal
voltage reference circuit. These benefits combine to produce
an exceptionally reliable voltage monitor circuit.
CC
= 0 V
CC
. Because of this design approach, interfacing these devices
Figure 10. Ensuring a Valid RESET Output Down to V
CC
falls below 0.8 V, the ADM809-5L/ADM809-5S
ADM809-5L/
ADM809-5S
GND
V
V
CC
CC
RESET
100kΩ
CC
= 0 V
Rev. B | Page 7 of 8
INTERFACING TO MICROPROCESSORS WITH
MULTIPLE INTERRUPTS
In a number of cases, it is necessary to interface to many
interrupts from different devices (for example, from thermal,
attitude, and velocity sensors). The ADM809-5L/ADM809-5S
can be easily integrated into existing interrupt-handling circuits
(see Figure 13) or used as standalone devices.
Figure 13. Additional Decoupling Can Be Achieved Using a 100 nF Capacitor
Figure 11. Interfacing to Microprocessors with Multiple Interrupts
Figure 12. Alternative Application Circuit with Extra Decoupling
ADM809
GND
V
V
CC
CC
RESET
3.3V
1
100nF
100nF
1
GND
PRIORITY ENCODER
GND
Between V
ADM809-5L/
ADM809-5S
ADM809-5L/
ADM809-5S
74LS147
3.3V
ADM809-5L/ADM809-5S
V
CC
3
V
3
CC
CC
RESET
RESET
and Ground
OTHER SENSING
2
2
DEVICES
47kΩ
47kΩ
22kΩ
4-LINE BCD TO
MICROPROCESSOR