Hardware+Design V1.07

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3.6.1 Pin Description
Table 17: Pin description
Pin name Pin No. Function
I2C_SDA 56 Serial interface data input and output
I2C_SCL 55 Serial interface clock input
3.6.2 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.
3.6.3 Design Guide
For SIM5320, 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.
3.7 Keypad Interface
SIM5320 module provides a keypad interface that supports five sense lines, or columns, and five keypad
rows. The interface generates an interrupt when any key is pressed. Its operation voltage is 1.8V.
3.7.1 Pin Description
SIM5320_Hardware Design_V1.07 2012-09-21
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