User's Manual

M50 Hardware Design
M50_HD_V2.0 - 56 -
Table 16: Pin definition of the SIM interface
In Figure 33, the pin SIM_PRESENCE is used to detect whether the tray of the Molex SIM socket,
which is used for holding SIM card, is present in the card socket. When the tray is inserted in the
socket, SIM_PRESENCE is at low level. Regardless of whether the SIM card is in the tray or not,
the change of SIM_PRESENCE level from high to low level inspires the module to reinitialize
SIM card. In default configuration, SIM card detection function is disabled. Customer’s
application can use “AT+QSIMDET=1,0 ” to switch on and “AT+QSIMDET=0,0 ” to switch off
the SIM card detection function. For detail of this AT command, please refer to the document [1].
When “AT+QSIMDET=1,0” is set and the tray with SIM card is removed from SIM socket, the
following URC will be presented.
+CPIN: NOT READY
When the tray with SIM card is inserted into SIM socket again and the module finishes
re-initialization SIM card, the following URC will be presented.
Call Ready
Module
SIM_VDD
SIM_GND
SIM_RST
SIM_CLK
SIM_DATA
SIM_PRESENCE
22R
22R
22R
VDD_EXT
10K
100nF SIM_Holder
GND
GND
ESDA6V8V6
33pF33pF 33pF 33pF
VCC
RST
CLK
IO
VPP
GND
GND
Figure 33: Reference circuit of the 8 pins SIM card
Name Pin Description
SIM_VDD 56 Supply power for SIM Card. Automatic detection of
SIM card voltage. 3.0V±10% and 1.8V±10%.
Maximum supply current is around 10mA.
SIM_DATA 54 SIM data
SIM_CLK 55 SIM clock
SIM_RST 53 SIM reset
SIM_PRESENCE 57 SIM card detection
SIM_GND 52 SIM ground
Quecctel
Confidential