S-35730C01A-K8T2U Datasheet, PDF (10/20 Pages) Seiko Instruments Inc – CONVENIENCE TIMER

FOR AUTOMOTIVE 125°C OPERATION CLOCK PULSE OUTPUT WITH FREQUENCY SETTING PIN CONVENIENCE TIMER
S-35730 Series
Rev.1.1_00
 Power-on Detection Circuit
In order for the power-on detection circuit to operate normally, raise the power supply voltage of the IC from 0.2 V or lower
so that it reaches 1.8 V of the operation power supply voltage minimum value within 10 ms, as shown in Figure 9.
Within 10 ms
1.8 V
(Operation power
supply voltage min.)
0.2 V or lower
0 V^*1
*1. 0 V means that there is no potential difference between the VDD pin and the VSS pin of the S-35730 Series.
Figure 9 How to Raise Power Supply Voltage
If the power supply voltage of the S-35730 Series cannot be raised under the above conditions, the power-on detection
circuit may not operate normally and an oscillation may not start. In such case, perform the operations shown in
"1. When power supply voltage is raised at ENBL pin = "L" " and "2. When power supply voltage is raised at
ENBL pin = "H" ".
1. When power supply voltage is raised at ENBL pin = "L"
Set the ENBL pin to "L" until the power supply voltage reaches 1.8 V or higher. While the ENBL pin is set to "L", the
oscillation start signal becomes "H", and the crystal oscillation circuit normally oscillates. If the ENBL pin is set to "H"
after the power supply voltage reaches 1.8 V, the oscillation start signal becomes "L" within 500 ms, and the
oscillation status is maintained.
10 ms
1.8 V
(Operation power supply voltage min.)
0.2 V or lower
0 V^*1
ENBL pin input
Oscillation start signal "H"  "L"
within 500 ms
Oscillation start signal
Crystal oscillation
circuit output
*1. 0 V means that there is no potential difference between the VDD pin and the VSS pin of the S-35730 Series.
Figure 10 When Power Supply Voltage is Raised at ENBL Pin = "L"
10