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Notice: The information in this document is subject to change without notice

Low Power, 5V µP Reset

ASM1810

February 2005

rev 1.4

Application Information

Operation - Power Monitor

The

ASM1810

detects

out-of-tolerance

power

supply

conditions. It resets a processor during power-up, power-down

and issues a reset to the system processor when the monitored

power supply voltage is below the reset threshold. When an

asserted. On power-up, RESET is kept active (LOW) for

approximately 150ms after the power supply voltage has

reached the selected tolerance. This allows the power supply

and microprocessor to stabilize before RESET is released.

Output Conditions

remains above 1.2V. However the RESET output on the

ASM1810 uses a push-pull drive stage that can maintain a valid

resistor can be connected from the reset pin (RESET) to

Ground (see Figure 1). This configuration will give a valid value

power up and down, this configuration will draw current when

the RESET is in the high state. A value of 100k

Ω should be

adequate to maintain a valid connection.

Microprocessor

RESET

RESET

ASM1810

100kΩ

RESET

Figure 2: Timing Diagram: Power-Up

RESET

Figure 3: Timing Diagram: Power-Down