S-35730C01A-K8T2U Datasheet, PDF (9/20 Pages) Seiko Instruments Inc – CONVENIENCE TIMER

FOR AUTOMOTIVE 125°C OPERATION CLOCK PULSE OUTPUT WITH FREQUENCY SETTING PIN CONVENIENCE TIMER
Rev.1.1_00
S-35730 Series
 FOUT Pin Clock Pulse Output
1. Options of clock pulse frequency
4 types of FOUT pin clock pulse output can be selected as the option from the frequency of 1 Hz to 32.768 kHz.
Table 8 shows the pin settings and the list of options for the FOUT pin clock pulse frequency.
Pin Setting
SET0 SET1
L
L
L
H
H
L
H
H
Table 8 List of Options
Clock Pulse
Frequency 1
32.768 kHz
128 Hz
2.048 kHz
8 Hz
Clock Pulse
Frequency 2
16.384 kHz
64 Hz
1.024 kHz
4 Hz
Clock Pulse
Frequency 3
8.192 kHz
32 Hz
512 Hz
2 Hz
Clock Pulse
Frequency 4
4.096 kHz
16 Hz
256 Hz
1 Hz
For example, when the pin setting is SET0 pin = "L" and SET1 pin = "L", 1 clock pulse frequency can be selected from
"32.768 kHz", "16.384 kHz", "8.192 kHz" and "4.096 kHz". The others cannot be selected.
Table 9 shows the example of the clock pulse frequency combination.
Table 9 Example of Options
Pin Setting
SET0 SET1
L
L
L
H
H
L
H
H
Clock Pulse Frequency
32.768 kHz
32 Hz
1.024 kHz
1 Hz
2. ENBL pin and clock pulse output of FOUT pin
The FOUT pin outputs the clock pulse when the ENBL pin is "H". The FOUT pin is fixed to Nch open-drain output = "H"
or CMOS output = "L" when the ENBL pin is "L". Since the input signal of the ENBL pin is not synchronized with the
clock pulse output from the FOUT pin, the duty ratio may change when the "H" and "L" of the ENBL pin changes.
The example of the FOUT pin output timing is shown below.
ENBL
ON
FOUT
OFF
Figure 7 Example FOUT Pin Output Timing (Nch Open-drain Output)
ENBL
ON
FOUT
OFF
Figure 8 Example of FOUT Pin Output Timing (CMOS Output)
The SET0 pin and the SET1 pin input signals are not synchronized with the clock pulse output from the FOUT pin as
well. Therefore, duty ratio may change if the SET0 pin and the SET1 pin settings are changed when the ENBL pin is "H".
Moreover, since the crystal oscillation circuit is unstable immediately after power-on, regardless of the status of the
ENBL pin, the FOUT pin is fixed to Nch open-drain output = "H" or CMOS output = "L" for about 0.5 seconds after
power-on.
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