Data Sheet

ADM1810 to ADM1813/ADM1815 to ADM1818

Rev. F | Page 7 of 12

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.

Figure 9. Power-Down Timing Diagram

Figure 10. Power-Up Timing Diagram

ADM1813 AND ADM1818

The ADM1813 and ADM1818 are low cost voltage monitoring

devices featuring an open-drain with internal pull-up resistor

output and optional push-button reset function.

Figure 11. ADM1813/ADM1818 Typical Application

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.

Figure 12. Push-Button Reset Timing Diagram

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.

Figure 13. ADM1810/ADM1812/ADM1815/ADM1817 Typical Application

ADM1811 AND ADM1816

The ADM1811 is a 5 V supply monitor with an active low open-

drain with internal pull-up resistor output and trip point options of

4.62 V and 4.35 V typical. The ADM1816 also has an active low

open-drain with internal pull-up resistor output but is suitable

for monitoring lower voltage supplies of 3.3 V, 3 V, and 2.5 V.

Figure 14. ADM1811/ADM1816 Typical Application

DELAY

RST

RESET ACTIVE TIMEOUT

RST

ADM1813/

ADM1818

GND

RST

MICRO-

PROCESSOR

RESET

VOLTAGE

INPUT HIGH

PUSH-BUTTON TIME

RESET TIMEOUT

VOLTAGE

INPUT LOW

ADM1810/

ADM1812/

ADM1815/

ADM1817

GND

RST/RST

MICRO-

PROCESSOR

RESET

ADM1811/

ADM1816

GND

RST

MICRO-

PROCESSOR

RESET