AN2504 datasheet(9/14 Pages) STMICROELECTRONICS

Part #	AN2504

Description	Using STMicroelectronics Voltage Detectors

PDF	14 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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9 / 14 page

AN2504 - Application note

Simulation of the Reset Time-out Period

9/14

Simulation of the Reset Time-out Period

It is possible to simulate reset time-out period with an RC element on the output of voltage

detector (see Figure 9).

Figure 9.

Hardware Hookup with RC element on the Voltage Detector Output

If the supply voltage, VCC, drops below the defined voltage threshold, VRST, the capacitor, C,

is discharged through the output transistor of the voltage detector (see Figure 10).

When the supply voltage, VCC, rises above the voltage threshold plus hysteresis,

VRST +VHYST, the output transistor disconnects the output from the ground and the

capacitor, C, is charged through the resistor, R.

Figure 10.

Voltage Waveforms

AI12911a

VSS

VCC

MCU

VCC

Suspend

VCC

STM1061N

OUT

VSS

VCAP

AI12912

VIH

VRST

VCAP

VCC

VRST – VHYST

Capacitor is charging

Capacitor is

discharging

AN2504 Datasheet(PDF) 9 Page - STMicroelectronics