GSM/GPRS Module
M85 Hardware Design
M85_Hardware_Design Confidential / Released 53 / 92
Please do not use ―AT+QSIMDET=1,1‖ which causes to initialize SIM card when Figure 33 circuit is
adopted.
If the SIM1 card detection function is not used, keep SIM_PRESENCE pin open. The reference circuit for
a 6-pin SIM card socket is illustrated as the following figure.
Module
SIM1_VDD
SIM_GND
SIM1_RST
SIM1_CLK
SIM1_DATA
SIM1_PRESENCE
22R
22R
22R
100nF
SIM_Holder
GND
ESDA6V8V6
33pF33pF 33pF
VCC
RST
CLK
IO
VPP
GND
GND
33pF
Figure 34: Reference Circuit for SIM1 Interface with the 6-pin SIM Card Holder
The following figure is the reference design for SIM2 interface with the 6-pin SIM card holder.
Module
SIM2_VDD
SIM_GND
SIM2_RST
SIM2_CLK
SIM2_DATA
22R
22R
22R
100nF
SIM_Holder
GND
ESDA6V8V6
33pF33pF 33pF
VCC
RST
CLK
IO
VPP
GND
GND
33pF
Figure 35: Reference Circuit for SIM2 Interface with the 6-pin SIM Card Holder
NOTE
Quectel
Confidential