3 Application Interfaces
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Figure 5. Power-on sequence
Before pulling down the PWRKEY pin, make sure that the VBAT voltage is stable. It is
recommended that the time interval between VBAT power-on and pulling PWRKEY pin down
be no less than 30ms, and the time for pulling PWRKEY pin down is recommended to last for
2 s (the minimum time for pulling PWRKEY down is 700ms).
One way is to use an OC/OD drive circuit to control the PWRKEY pin. The reference circuit
is shown in the following figure.
Figure 6. OC/OD drive reference circuit
The other way is to use a button switch. A TVS (ESD9X5VL-2/TR is recommended) should
be located close to the button to implement ESD protection. The reference circuit is shown in
the following figure.
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