MeiG_SLM550_Hardware Design Manual
MeiG Smart Technology Co., Ltd
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4.9.1 USB OTG
The SLM550 module can provide USB OTG function. The pins used in this function are as follows:
Table 13 USB OTG Pin Description
Pin name
Pin
Description
VBUS
141, 142
5V charging input / OTG output power.
USB_HS_DM
13
USB Date-
USB_HS_DP
14
USB Date+
USB_HS_ID
16
USB ID
The recommended circuit diagram of USB OTG is as follows:
Figure 32 USB-OTG Connection Diagram
4.10 Charging Interface
The SLM550 module integrates a 2A 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 charge: It is divided into two parts, trickle charge-A: when the battery voltage is lower than 2.8V,
the charging current is 90mA; trickle charge-B: when the battery voltage is between 2.8V and 3.2V, the
charging current is 450mA;
Constant current charging: when the battery voltage is between 3.2V~4.2V, the charging current is
1.44A when the adapter is charging, and the charging current is 450mA when the USB is charging;
Constant voltage charging: When the battery voltage reaches 4.2V, constant voltage charging, the
