MeiG Smart product technical information
SLM500
Hardware Design Guide
Page 48
The recommended circuit diagram of USB OTG is as follows:
Figure 4.27: USB-OTG Connection Diagram
4.10. Charging Interface
The SLM500 module integrates a 1.44A charging solution. The charging related content of
this manual is only described by the internal charging scheme. The QCM2150 platform uses
the Qualcomm PM215 internal integrated charging chip by default. The chip is in liner mode.
Trickle charging: it is divided into two parts: trickle charging-A: the charging current is
90mA when the battery voltage is lower than 2.8V; trickle charging-B: the charging current is
450mA when the battery voltage is between 2.8V and 3.2V;
Constant current charging: when the battery voltage is between 3.2V ~ 4.2V, the charging
current is 1.44A , when charging with USB is 450mA;
Constant voltage charging: when the battery voltage reaches 4.2V, the charging current
gradually decreases, and the charging current reduces to about 100mA to stop charging.
Figure 4.28: Charging diagram