CF5761 Datasheet, PDF (7/10 Pages) Nippon Precision Circuits Inc – CMOS Analog Clock IC with Alarm Function

CF5761 series
Alarm Control
The alarm is controlled using AI, SN, and SEL inputs. These pins have built-in chattering elimination circuits
to prevent incorrect operation due to input chatter. The alarm output timing in response to these inputs is shown
in the following figure.
Input
Function
AI
Alarm control input.
When AI is active, the specified alarm pattern is output on AO1, AO2 and AO3.
SN
Snooze function control input.
When the snooze input is accepted, the snooze time count begins. The snooze time is 300s.
Alarm function select input.
SEL Selects one of two alarm patterns. When SEL is switched (from HIGH to LOW, or LOW to
HIGH), the snooze state and auto-stop function is released, and the alarm signal is output.
Input chatter elimination
t_ON < 62.5ms, the input is not accepted.
t_ON > 125ms, the input is accepted.
62.5ms ≤ t_ON ≤ 125ms, the input state is
undefined.
ON
AI
OFF
ON
SN
OFF
B
SEL
A
A
5min
B
A
B
5min
5min
Alarm output A
AB
BA
B
5min 5min
A
5min 5min
B
BA
Alarm
stops
Snooze
released
Auto-stop Auto-stop
released
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