CF5761 Datasheet, PDF (8/10 Pages) Nippon Precision Circuits Inc – CMOS Analog Clock IC with Alarm Function

CF5761 series
Alarm Modes
The CF5761 series provide several alarm modes and various alarm pattern outputs for a wide range of clock
specifications, as described in the following table.
Alarm mode
Simple alarm
Step tone
modulated alarm
Step volume
modulated alarm
Mode description
Output
Device
A fixed alarm pattern is repeatedly rung (basic mode).
Motor bell
Piezo-electric speaker CF5761CA/EA/HA/LB/MB
Electromagnetic speaker
At fixed intervals, the alarm pattern changes, increasing the tone pitch
with each step.
Motor bell
CF5761EA
At fixed intervals, using a fixed alarm pattern, the output waveform duty
changes, increasing the volume with each step.
Piezo-electric speaker
Electromagnetic speaker
CF5761LB/MB/NB
The alarm pattern timing for each device in the CF5761 series is shown in the series lineup.
The CF5761HA has a special modulated alarm pattern when SEL is HIGH, as shown in the following figure.
Outputs AO1 and AO3 have a frequency modulated alarm waveform output at the alarm fundamental fre-
quency of 4kHz (4096Hz). The modulation pattern is output on AO2.
62.5msec 62.5msec
AO1 output
1sec
187.5msec
437.5msec
AO3 output
AO2 output
Power-ON Initialization
The CF5761 series are reset to the following conditions after power is applied.
I AI, SN, SEL input state
These inputs are reset to LOW, except where the device has an active-LOW input in which case it is reset to
HIGH. See the series lineup table.
I O1, O2
In step movement devices, both outputs are HIGH and subsequent output occurs on O1. In sweep movement
devices, O1 is reset LOW and O2 is reset HIGH, and output starts immediately.
I AO1, AO2, AO3
No output after reset. However, F output (CF5761EA: 32kHz on AO3) and clock output start immediately.
I Test mode
Test mode is released after reset. Note that after the oscillator starts, the input state of each pin is read and
operation commences accordingly.
SEIKO NPC CORPORATION —8