Specifications

SIM7912&SIM7906 Hardware Design V1.02
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Module provides one integrated Universal Serial Bus (USB) interface which complies with the USB 3.0 and
2.0 specifications. This USB interface supports super speed (5Gbps) on USB 3.0 and high speed (480
Mbps) and full speed (12 Mbps) modes on USB 2.0.
The USB interface is used for AT command communication, data transmission, GNSS NMEA output,
firmware upgrade and software debugging.
The following table shows the pin definition of USB interface.
Table 15: Definition of USB interface
Pin name
Pin no.
I/O
Functional description
Comment
USB_VBUS
32
PI
USB VBUS detection
Typical 5.0V
Not support for charging
USB_ DP
34
AIO
Differential USB bi-directional data
plus
Required 90Ω
differential impedance
Compliant with USB 2.0
standard specifications
USB_ DM
33
AIO
Differential USB bi-directional data
minus
USB_SS_TX
_P
38
AO
USB3.0 super-speed transmit data
plus
Required 90Ω differential
Impedance
Compliant with USB 3.0
standard specifications
USB_SS_TX
_M
37
AO
USB3.0 super-speed transmit data
minus
USB_SS_
RX_P
40
AI
USB3.0 super-speed receive data plus
USB_SS_RX
_M
41
AI
USB3.0 super-speed receive data
minus
USB_ID
36
DI
OTG identification
1.8V power domain.
If unused, keep it open
OTG_PWR_
EN
143
DO
OTG power control
1.8V power domain.
If unused, keep it open
The following figure is the USB reference circuit.