CLM920_AC3 Module Hardware Usage Guide
Shanghai Yuge Information Technology co., LTD
- 29 -
3.7.1 USIM card reference circuit
The CLM920 AC3 module does not come with a USIM card slot. Users need to design a
USIM card slot on their own interface board. USIM card interface reference circuit is as
follows
：
Figure 3-17 USIM design circuit diagram
The USIM interface cable is recommended to use ONSEMI's SMF15C device for ESD
protection. The peripheral circuit components should be placed close to the card holder,
and the SIM card holder is close to the module layout.
The USIM card circuit is susceptible to radio frequency interference and does not
recognize or drop the card. Therefore, the card slot should be placed as far as possible
VOH
VDD-
0.45
3.05
VOL
0
0
0.45
16
USIM_
CLK
DO
USIM
card
clock
VOH
VDD-
0.45
3.05
USIM_VDD:
3.0V/1.8V
VOL
0
0
0.45
17
USIM_
RST
DO
USIM
card
reset
VOH
VDD-
0.45
3.05
USIM_VDD:
3.0V/1.8V
VOL
0
0
0.45
