Smart Machine Smart Decision
SIM800H _Hardware Design_V2.03
22
2016-10-10
VBAT
MIN:3.0V
Figure 9: The minimal VBAT voltage requirement at VBAT drop
Note: Hardware power down voltage is 3.0V.
4.1.2.
Monitoring Power Supply
AT command “AT+CBC” can be used to monitor the VBAT voltage. For detail, please refer to
document [1]
.
4.2.
Power on/off Scenarios
4.2.1.
Power on SIM800H
Customer can power on SIM800H by pulling down the PWRKEY pin for at least 1 second and release. This pin
is already pulled up to VBAT in the module internal, so external pull up is not necessary. Reference circuit is
shown as below.
4.7K
47K
Turn on/off
impulse
PWRKEY
Power
on/down logic
100K
VBAT
Module
1K
Figure 10:
Powered on/off module using transistor
PWRKEY
Power
on/down logic
100K
VBAT
Module
1K
Figure 11: Powered on/off module using button
The power on timing is illustrated as in the following figure.
SIMCOM
CONFIDENTIAL
FILE
