Smart Module Series
SC690A_Series_Hardware_Design 36 / 105
3
Operating Characteristics
3.1. Power Supply
3.1.1. Power Supply Pins
The module provides 3 VBAT pins, and 2 VPH_PWR pins. VBAT pins must be connected to an external
power supply to power the module. VPH_PWR pins are used to power other devices.
3.1.2. Battery Charge and Management
The module can recharge batteries. The battery charger in the module supports trickle charging,
constant current charging and constant voltage charging modes, which optimize the charging procedure
for Li-ion batteries.
⚫
Trickle charging:
When the battery voltage is below 2.1 V, a 75 mA trickle charging current is
applied to the battery.
⚫
Pre-charge mode:
When the battery voltage is charged up and is between 2.1 V and 3.0 V (the
maximum pre-charge voltage is 2.4
–3.0 V programmable, 3.0 V by default), the system will enter
into pre-charge mode. The charging current is 450 mA (100
–450 mA programmable, 450 mA by
default).
⚫
Constant current mode (CC mode):
When the battery is increased to 3 V, the system will switch to
CC mode. The maximum charging current is 3000 mA when an adapter is used for battery charging,
and the maximum charging current is 500 mA for USB charging.
⚫
Constant voltage mode (CV mode):
When the battery voltage reaches the final value 4.35 V, the
system will switch to CV mode and the charging current will decrease gradually. When the battery
level reaches 100 %, the charging is completed.
Table 7: Pin Definition of Charging Interface
Pin Name
Pin No.
I/O
Description
Comment
USB_VBUS
41, 42
PIO
Charging power input.
Power supply for OTG
device. USB/adaptor
insertion detection.
USB On-The-Go (OTG) supports
up to 1.0 A.
