CF5761 series

SEIKO NPC CORPORATION —8

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.

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.

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.

Alarm mode

Mode description

Output

Device

Simple alarm

A fixed alarm pattern is repeatedly rung (basic mode).

Motor bell

Piezo-electric speaker

Electromagnetic speaker

CF5761CA/EA/HA/LB/MB

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

changes, increasing the volume with each step.

Piezo-electric speaker

Electromagnetic speaker

CF5761LB/MB/NB

AO1 output

62.5msec 62.5msec

437.5msec

1sec

187.5msec

AO3 output

AO2 output