SC20-W_Manual_R1.0 Confidential / Released 14 / 41
3.3.
Power Supply
SC20-W provides two VBAT pins dedicated to connection with the external power supply. The two
VBAT_BB pins are used for module baseband part. The power supply range of the module is 3.5V~4.2V,
and the recommended value is 3.8V.
3.4.
Turn on and off Scenarios
3.4.1.
Turn on Module Using the PWRKEY
The module can be turned on by driving PWRKEY pin to a low level for at least 1.6s. PWRKEY pin is
pulled to 1.8V internally. It is recommended to use an open drain/collector driver to control the PWRKEY.
A simple reference circuit is illustrated in the following figure.
Turn on pulse
PWRKEY
4.7K
47K
≥1.6s
R1
R2
Q1
Figure 3: Turn on the Module Using Driving Circuit
The other way to control the PWRKEY is using a button directly. A TVS component is indispensable to be
placed nearby the button for ESD protection. A reference circuit is shown in the following figure.
PWRKEY
S1
Close to S1
TVS
Figure 4: Turn on the Module Using Keystroke
