User's Manual

Smart Machine Smart Decision
SIM5320_Hardware Design_V1.01 2011-11-10
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3.5.1 Pin Description
Table 12: Pin description
3.5.2 Signal Description
Both SDA and SCL are bidirectional lines, connected to a positive supply via a pull-up resistor
respectively. When the bus is free, both lines are high.
3.5.3 Design Guide
For SIM5320AD, the data on the I2C bus can be transferred at rates up to 400kbps. The number of
peripheral devices connected to the bus is solely dependent on the bus capacitance limit of 400pF. Note
that PCB traces length and bending are in users’ control to minimize load capacitance.
Note
I2C_SDA and I2C _SCL have been pulled up with two 2.2kR resistors to 2.6V level in module. So there is no need
to pull them up in users’ application circuit.
3.6 USB Interface
SIM5320AD module contains a USB interface. This interface is compliant with the USB2.0 specification.
The USB2.0 specification requires hosts such as the computer to support all three USB speeds, namely
low-speed (1.5Mbps), full-speed (12Mbps) and high-speed (480Mbps). USB charging and USB-OTG is
not supported.
Table 13: Electronic characteristic
Input voltage scope( V )
Pin name Pin No.
Min Typ Max
USB_VBUS 11 4.4 5.0 5.25
USB_DP 13
USB_DM 12
They are compliant with the USB 2.0 specification.
Pin name Pin No. Function
I2C_SDA 56 Serial interface data input and output
I2C_SCL 55 Serial interface clock input