AN2716

Timing definitions

Doc ID 14460 Rev 2

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Appendix A

Timing definitions

When the AC switch is OFF (not controlled or failed in open circuit), an IAC current flows

through the STCC08 AC input. The value of this current depends on RAC and Rshunt

resistors, the AC line voltage and the AC load impedance. The AVF signal toggles between

VCC and zero level (GND) for an IAC current value noted IACT (see Figure 17).

Figure 17.

Detection window width of the AC switch state

R and L are AC load characteristics, and

AC line voltage.

VLine

IAC

AVF

IACT

-IACT

f

t

´

=

2

1

2

t (s)

t (s)

ϕ

1

t

2

t

0

t

F

t

x

=

2

1

A

C

B

AC