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ADVANCED COMMUNICATIONS & SENSING

DATASHEET

SX8124

24 hours timer synchronized on 50/60Hz mains

ACS - Revision 2.4

October 2010

© Semtech Corp.

10

LED output

The LED output is used to indicate the status of the internal system. The LED signal is made of bursts of 4 us

pulses with a period of 30 us and total duration of 250 ms. This makes possible to activate a LED even at very

low voltage.

To indicate that OUT is high, the LED sends two bursts separated by 500 ms every 5 seconds.

To indicate that OUT is low, the LED send one burst every 5 seconds.

To indicate that the system is not synchronized (no PHASE detected, or frequency measured on PHASE

outside 50-60 Hz, at start-up or after a manual reset), the LED continuously sends bursts separated by 250

ms.

10.1

Synchronized on phase, outputs ON

When synchronized, the LED indicates the OUT pin status. The first pulse occurs 5 seconds after a POR, timer

startup or timer reset,

10.2

Synchronized on phase, outputs OFF

The first pulse occurs 5 seconds after a POR, timer startup or timer reset,

Figure 15. Dual pulse

Figure 16. Single pulse

LED

250ms

500ms

250ms

250ms

500ms

250ms

5s

OUT

NOUT

LED

250ms

250ms

5s

5s

OUT

NOUT