ADM1818 Analog Devices, ADM1818 Datasheet - Page 7

• Manufacturer Part Number: ADM1818
• Description: Microprocessor Supervisory in SOT-23 with Manual Push Button Option
• Manufacturer: Analog Devices

Specifications of ADM1818

• # Of Monitored Voltages: 1
• Backup-battery Switch: No
• Manual Reset Capability: Yes
• Package: SC70,SOT
• Reset Threshold Summary: 5 Options--2.18 to 3.06V
• Reset Output-stage: Active-Low/Open-Drain
• Min Reset Timeout (ms): 100
• Watchdog Timer: No

THEORY OF OPERATION
TIMING DIAGRAMS FOR ALL DEVICES
The following two timing diagrams are valid for ADM1810,
ADM1811, ADM1812, ADM1813, ADM1815, ADM1816,
ADM1817, and ADM1818.
ADM1813 AND ADM1818
The ADM1813 and ADM1818 are low cost voltage monitoring
devices featuring an open-drain output and optional push-button
reset function.
An optional push-button reset switch can be connected between
RST and ground. Pressing this switch pulls the reset output low. If
the push-button reset button pulls the RST output low for a period
greater than 1 μs when the reset button releases the RST line to
float high, then the RST line stays low for another 150 ms typical.
V
CC
TRIP POINT (MIN)
Figure 11. ADM1813/ADM1818 Typical Application
V
RST
RST
V
V
CC
CC
CC
TRIP POINT (MAX)
Figure 9. Power-Down Timing Diagram
V
Figure 10. Power-Up Timing Diagram
CC
V
V
CC
CC
ADM1813/
ADM1818
V
GND
TRIP POINT
TO RESET
CC
DELAY
V
RST
CC
RESET ACTIVE TIMEOUT
V
TRIP POINT
CC
TRIP POINT (MAX)
V
PROCESSOR
RESET
CC
MICRO-
TRIP POINT (MIN)
V
OL
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ADM1810 to ADM1813/ADM1815 to ADM1818
The ADM1818 range has 2.88 V and 2.55 V (typical) trip point
options that allow the user to monitor 3.3 V and 3 V supplies.
For 5 V monitoring requirements, the ADM1813 range has 4.62 V
and 4.35 V (typical) trip point options.
ADM1810, ADM1812, ADM1815, AND ADM1817
The ADM1812 is a 5 V supply monitor with an active high push-
pull output and trip point options of 4.62 V and 4.35 V typical.
The ADM1810 is similar to the ADM1812, except that the
ADM1810 has an active low push-pull output stage. The ADM1817
is suitable for monitoring 3.3 V, 3 V, and 2.5 V supplies, with an
active high push-pull output and trip point options of 3.06 V,
2.88 V, 2.55 V, 2.31 V, and 2.18 V typical. The ADM1815 is similar
to the ADM1817, except that the ADM1815 has an active low
push-pull output stage.
The ADM1810/ADM1812/ADM1815/ADM1817 can connect
directly to most microprocessor reset inputs without the need for
external components.
ADM1811 AND ADM1816
The ADM1811 is a 5 V supply monitor with an active low open-
drain output and trip point options of 4.62 V and 4.35 V typical.
The ADM1816 also has an active low open-drain output but is
suitable for monitoring lower voltage supplies of 3.3 V, 3 V,
and 2.5 V.
INPUT LOW
Figure 13. ADM1810/ADM1812/ADM1815/ADM1817 Typical Application
VOLTAGE
Figure 14. ADM1811/ADM1816 Typical Application
Figure 12. Push-Button Reset Timing Diagram
PUSH-BUTTON TIME
V
V
CC
CC
ADM1810/
ADM1812/
ADM1815/
ADM1811/
ADM1817
ADM1816
V
GND
V
GND
CC
CC
RST/RST
RST
RESET TIMEOUT
PROCESSOR
PROCESSOR
RESET
RESET
MICRO-
MICRO-
VOLTAGE
INPUT HIGH