User's Manual

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H380-GL Hardware User Manual Page
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Figure 3- 5 Circuit for Automatic Start-up
3.3.1.2 Start-up Timing
After the module is powered on, when the FUL_CARD_POWER_OFF# signal pulls up and exceeds 20ms
(the recommended value is 100ms), the module starts up. Meanwhile, VSD2_1V8 inside the module
outputs 1.8V voltage, and the module begins the process of start-up initialization. The start-up timing is
shown in Figure 3-6:
Figure 3-6 Start-up Timing Control Diagram
Note:
VSD2_1V8 is a PMU inside the module, it outputs 1.8V voltage and has not been led out via M.2
interface, the appearance of this voltage in timing chart is mainly purposed to facilitate the
understanding of timing;
RESET# is required to delay its pull-up for 1s compared with +3.3V, because the module needs
time for power-on of +3.3V power supply (capacitor charging). If +3.3V maintains as ordinary
power supply, then the delay time is negligible.