Silan

Semiconductors

SC8560

HANGZHOU SILAN MICROELECTRONICS CO.,LTD.

Rev: 1.1

2003.06.26

5

(Continued)

Terminal Description

Operating Description

Power Failure Detection display

If the power supply voltage drops and is applied again, all the on-segments flash

and the power failure indication mode is entered. The power failure indication

Alarm Operation and Alarm

Output

The alarm signal outputs when alarm content marches the time .When not reset

by either snooze input or alarm off input, output continues after l hour and 59

minutes. This output signal consists of 900 Hz 2 Hz intermittent (50% duty)

modulation signals. When the need arises, a filter can be applied to alter the alarm

signal to a DC signal.

Snooze Input

When the alarm is sounding and instantly activating Vss to this pin, alarm output is

set to OFF for a period between 8 and 9 minutes after which time the alarm signal

is once again output .The snooze function can be used repeatedly in l hour and 59

minutes intervals. A pull-down resist is built-in. Activating Vss to the snooze pin

when the alarm is OFF resets the sleep timer counter to [0:00].(This is known as

the one-touch sleep timer reset function.)

Alarm Off Input

Activating this input pin to Vss instantly sets alarm output to OFF. A pull-down

resistor is built-in.

Sleep Timer and Sleep Output:

Sleep output can turn on the radio and can be set for time intervals of 59 minutes

or l hour and 59 minutes. Refer to Table 2 for the proper selection procedure (59

minutes or l hour and 59 minute selection). This sleep timer is constructed using a

down counter and when the counter content arrives at [00], output is set to off and

the radio turns off .Adding Vss to snooze input turns sleep output off, when sleep

output is on.

TABLE 1: DISPLAY MODES

Selective

Input

Alarm

Sleep

Display Mode

Digit No.1

Digit No.2

Digit No.3

Digit No.4

NC

NC

Time display

10’s place for

hour ,AM/PM

Hour

10’s place for

minute

Minute

Vss

NC

Alarm display

10’s place for

hour ,AM/PM

Hour

10’s place for

minute

Minute

NC

Vss

Sleep display

Clear

Hour

10’s place for

minute

Minute

Vss

Vss

Second display

Clear

Minute

10’s place for

second

Second

Note: Activating Vss using two inputs simultaneously (alarm select and sleep select), the display mode is switched

to display seconds.