Smart Machine Smart Decision
SIM7020_Hardware_Design_V1.02 18 2018-07-25
4.7K
47K
Turn on/
off
impulse
PWRKEY
Power
on
/
off
logic
VBAT
Module
1K
100nF
H
L
40K
Figure 6: Reference power on/off circuit
The power-on scenarios are illustrated in the following figure.
STATUS
(Output)
T
on
VBAT
PWRKEY
(Input)
T
on(status)
UART Port
不可用
可用
T
on(uart)
不可用
可用
USB Port
T
on(usb)
Figure 7: Power on timing sequence
Table 8: Power on timing and electronic characteristic
Symbol Parameter Min. Typ. Max. Unit
T
on
The time of active low level impulse of
PWRKEY pin to power on module
215 800 - ms
T
on(status)
The time from power-on issue to
STATUS pin output high level(indicating
power up ready )
440
ms
T
on(uart)
The time from power-on issue to UART
port ready
2
s
T
on(usb)
The time from power-on issue to USB 4 s