SX8124ISTRT SEMTECH [Semtech Corporation], SX8124ISTRT Datasheet - Page 9

• Manufacturer Part Number: SX8124ISTRT
• Description: 24 hours timer synchronized on 50/60Hz mains
• Manufacturer: SEMTECH [Semtech Corporation]

ACS - Revision 2.4
© Semtech Corp.
5
ADVANCED COMMUNICATIONS & SENSING
System architecture
The system is based on its internal timer to track frequency and to disciminate 50 Hz vs 60 Hz supply. If there
is no input on PHASE pin, the system timing will use the internal oscillator (10% precise).
Once the system is locked on the mains phase, its time precision is given by the mains frequency precision.
The period of the output signal on OUT and NOUT is 24 hours. The duty cycle on these pins is equal to the
relative voltage on pin DURATION version the voltage on pin VDD. If DURATION is 1/3 of VDD, OUT will be
high for 8 hours and down for 16 hours.
Remark that when the OUT state is manually modified using the START pin, this does not influence the
internal counter: the OUT (and NOUT) pins will continue to be switched “on” at the end of the 24 hours cycle
and “off” after the programmed duty cycle. The LED outputs is a signal indicating the internal chip status (see
10. LED
DURATION
output).
PHASE
START
LED
October 2010
ADC
Debounce
Burst gen
Oscillator
detect
detect
60 Hz
50 Hz
RC
Figure 4. SX8124 Architecture
Reset ‘0’
duration
detect
Set
3s detect
Page 9
Reset
TIMER
24 hours timer synchronized on 50/60Hz mains
24H
Output
control
www.semtech.com/products/
NOUT
VDD
OUT
VSS
SX8124
DATASHEET