Smart Module Series
SA800U-WF Hardware Design
SA800U-WF_Hardware_Design 40 / 106
1. It is recommended to switch off the power supply for the module in abnormal condition, and then
switch on the power to restart the module.
2. The module supports battery charging function by default. If battery is not used and the above power
supply design is adopted, make sure the charging function is disabled by software, or connect a
Schottky diode with higher than 5 A average current capacity between the output of the inductor L1
and the VBAT pins of the module.
3. When the battery voltage is below 3.1 V, the system will trigger automatic shutdown, so the design of
power supply should be consistent with the configuration of fuel gauge driver.
3.5. Turn on and off Scenarios
3.5.1. Turn on the Module Using PWRKEY
The module can be turned on by driving PWRKEY low for at least 1.6 s. PWRKEY is pulled up to 1.8 V
internally. It is recommended to use an open drain/collector driver to control PWRKEY. A simple
reference circuit is illustrated in the following figure.
Turn on pulse
PWRKEY
4.7K
47K
>1.6 s
R1
R2
Q1
R3
1K
Figure 6: Turn on the Module Using Driving Circuit
NOTES
