S-35720C01A-K8T2U Datasheet, PDF (11/21 Pages) Seiko Instruments Inc – Low current consumption

FOR AUTOMOTIVE 125°C OPERATION WITH INTERRUPT TIME SETTING PIN CONVENIENCE TIMER
Rev.1.1_00
S-35720 Series
 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 12.
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-35720 Series.
Figure 12 How to Raise the Power Supply Voltage
If the power supply voltage of the S-35720 Series cannot be raised under the above conditions, the power-on detection
circuit may not operate normally and an oscilla_{_}ti_{_}o_{__}n_{___}may not start^*1. In such case, perform the operations shown in
"_{__}1_{_}._{____}When power supply voltage is raised at RST pin = "L" " and "2. When power supply voltage is raised at
RST pin = "H" ".
*1. When one-shot loop time-out or handshake time-out is selected as the option.
_______
1. When power supply voltage is raised at RST pin = "L"
_______
_______
Set the RST pin to "L" until the power supply voltage reaches 1.8 V or higher. While the RST_{___}p_{__}in_{__} is set to "L", the
oscillation start signal becomes "H", and the crystal oscillation circuit normally oscillates. If the RST 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.
_______
The current consumption increases as mentioned below while the RST pin is set to "L".
• When the product without a pull-up resistor is selected:
• When the product with a pull-up resistor is selected:
10 ms
1.7 μA typ.
30 μA typ.
1.8 V
(Operation power supply voltage min.)
0.2 V or lower
0 V^*1
RST pin input
Oscillation start signal "H"  "L"
within 500 ms
Oscillation start signal
Oscillation circuit output
*1. 0 V means that there is no potential difference between the VDD pin and the VSS pin of the S-35720 Series.
_______
Figure 13 When Power Supply Voltage is Raised at RST Pin = "L"
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