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
Mode description
Output
Motor bell
Piezo-electric speaker
Device
Simple alarm
A fixed alarm pattern is repeatedly rung (basic mode).
CF5761CA/EA/HA/LB/MB
Electromagnetic speaker
Step tone
modulated alarm
At fixed intervals, the alarm pattern changes, increasing the tone pitch
with each step.
Motor bell
CF5761EA
Step volume
modulated alarm
At fixed intervals, using a fixed alarm pattern, the output waveform duty Piezo-electric speaker
changes, increasing the volume with each step. 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.
1sec
62.5msec 62.5msec
187.5msec
437.5msec
AO1 output
AO3 output
AO2 output
Power-ON Initialization
The CF5761 series are reset to the following conditions after power is applied.
ꢀ 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.
ꢀ 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.
ꢀ AO1, AO2, AO3
No output after reset. However, F output (CF5761EA: 32kHz on AO3) and clock output start immediately.
ꢀ 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
NPC [ NIPPON PRECISION CIRCUITS INC ]
