STM802LSLASHM datasheet(18/43 Pages) STMICROELECTRONICS

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Operation

STM690A/692A/703/704/802/805/817/818/819

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Doc ID 10522 Rev 10

2.11

Negative-going VCC transients

The STM690A/692A/703/704/802/805/817/818/819 Supervisors are relatively immune to

negative-going VCC transients (glitches). Figure 37 shows typical transient duration versus

reset comparator overdrive (for which the STM690A/692A/703/704/802/805/817/818/819

will NOT generate a reset pulse). The graph was generated using a negative pulse applied

to VCC, starting at VRST + 0.3 V and ending below the reset threshold by the magnitude

indicated (comparator overdrive). The graph indicates the maximum pulse width a negative

VCC transient can have without causing a reset pulse. As the magnitude of the transient

increases (further below the threshold), the maximum allowable pulse width decreases. Any

combination of duration and overdrive which lies under the curve will NOT generate a reset

signal. Typically, a VCC transient that goes 100 mV below the reset threshold and lasts 40 µs

or less will not cause a reset pulse. A 0.1 µF bypass capacitor mounted as close as possible

to the VCC pin provides additional transient immunity.

STM802L/M Datasheet(PDF) 18 Page - STMicroelectronics