VEXT Detect W/Keyboard Interrupts

20037928

*** = Internal signal

1.

VEXT goes active low.

2.

VEXT 32 msec de-bounce period.

3.

Delay between LDO1 and LDO2 enable.

4.

Both LDO1 and LDO2 outputs reach 95% of respective output voltage, start Reset timer.

5.

Reset delay.

6.

Keyboard de-bounce delay.

7.

Keyboard pulse must be a minimum of 32 msec.

8.

PS_HOLD may go low after Key press, but LDOs stay on since VEXT is low.

9.

VEXT goes high, begin shutdown since PS_HOLD is low.

10. Delay between RST going low and LDO2 disabled.

11. Delay between LDO2 disable and LDO1 disabled.

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