User Manual

Smart Machine Smart Decision
SIM7100_Hardware_Design_V1.02 2015-06-16
**VDD_EXT must be set with 2.95V output by AT command.
3.7.1 SD Design guide
VDD_EXT can provide power for SD card. ESD/EMI components should be arranged beside SD
card socket. Refer to the following application circuit.
TVS
33pF
TVS
33pF
TVS
33pF
TVS
33pF
TVS
33pF
TVS
33pF
100nF
4.7uF
Figure 27: SD Reference Circuit
Note: The SD signal lines have internal pull-up resistors for BOM saving.
3.8 I2C Interface
SIM7100 provides a I2C interface compatible with I2C specification, version 2.1, with clock rate
up to 400 kbps. Its operation voltage is 1.8V.
3.8.1 I2C Design Guide
The following figure shows the I2C bus reference design.
Figure 28: I2C Reference Circuit
Note ：
SDA and SCL do not have pull-up resistors in module. So, 2 external pull up resistors are