Specifications

Smart Machine Smart Decision
SIM5800_Hardware Design_V1.01 28 2018-10-08
1. In the download phase, the current limit is very small from the VCHG to the VBAT path , only
enough for the module to download the required current. Therefore, normal startup function of
the module cannot be realized through VBUS power supply.
2. If there are other chips in the module VBAT network which will consume the current when the
power on, if the current consumption is high, it will also cause the module download failure.
4.5.1USB HOST
The SIM5800 module can provide the function of USB HOST, but the module does not have the output of 5V
power supply. Therefore, when using this function, the customer needs the external circuit to add 5V output.
The detection order of USB_HOST is as follows: when the device is connected, an interrupt signal is generated by
USB_ID first, then the software controls GPIO to enable external +5V output, and finally the data on
USB_DP/DM is detected. The recommended circuit diagram is as follows:
Module
Connector
USB_DM
GND
GND
VBUS
VBUS
<1pF
USB_DP
USB_DM
USB_ID
USB_ID
USB_DP
+5V
Power
Enable
GPIO
Figure 18:USB_OTG diagram
4.6 Charge management
The SIM5800 supports the charging function, and users can charge the lithium battery through the VBUS pin. The
maximum charging current can be supported up to 1A (TBD).
VCHG
0.2R
VBAT
BAT_ID
GND
Battery
PMIC
VBUS