User's Manual
Table Of Contents
- Copyright
- Attention
- Trademark
- Versions
- Foreword
- Product Overview
- Structure
- Hardware Introduction
- Hardware Interface
- Power Interface
- Power on/off and Reset Signal
- Status Indicating Signal
- USB /SSIC Interface
- USIM Interface
- Digital Audio
- Win8/Android Switch Control Interface
- W_DISABLE# Interface
- TX_BLANKING Interface
- WAKEUP_Host Interface
- BODY_SAR Interface
- I2C Interface
- Clock Interface
- Config Interface
- RF Interface
- Other Interfaces
- Electrical and Environmental Features
- RF Interface
L830-EA M.2 Module Hardware User Manual Page
31
of
45
Figure 5- 8 Reference Design of “Normally Open” SIM Card Interface
Normally Open SIM Connector:
1）Pull out SIM card, pin 7 and pin 8 will disconnect.
2）Insert SIM card, pin 7 and pin 8 will short-circuit
Note:
In order to improve EMC performance, the SIM card slot should be close to the module to the largest
extent.
The filter capacitor on the SIM-card signal circuit should be placed close to SIM card pin to the largest
extent.
ESD device (like TVS) shall be added to the SIM-card signal circuit protection. ESD device should be
placed close to SIM card pin.
SIM card connector shall be with shielding function, to improve the anti-jamming capability of SIM
card
SIM1_CD signal connection supports hot-plugging; active high level by default(change to active low
through AT commands ). If the module detects the signal at high level, it means there is a card in the
module.
5.5.3 Points for Attention in USIM Design
SIM card interface design is very important for the normal operation of the module and SIM card.
The following points need to be complied with during the design:
SIM card layout and wiring must keep away from EMI interference source, like RF antenna and digital