
Reproduction forbidden without Fibocom Wireless Inc. written authorization - All Rights Reserved.
FIBOCOM L860-GL Series Hardware Guide
Page 40 of 60
when the SIM_DETECT pin is high, then executes the initialization program and finish the network
registration after reading the SIM card information. When the SIM_DETECT pin is low, the module
determines that the SIM card is detached and does not read the SIM card.
Note:
SIM_DETECT is active high. It can be swapped to active low by AT CMD.
USIM Design
The SIM card circuit design should meet the EMC standards and ESD requirements with the improved
capability to resist interference, to ensure that the SIM card can work stably. The following guidelines
should be noted in design:
The SIM card slot should be placed as close as possible to the module, and away from the RF antenna,
DC/DC power supply, clock signal lines, and other strong interference sources.
The SIM card slot with a metal shielding housing can improve the anti-interference ability.
The trace length between the SIM card slot and the module should not exceed 100mm, or it could
reduce the signal quality.
The UIM_CLK and UIM_DATA signal lines should be isolated by GND to avoid crosstalk interference.
If it is difficult for the layout, the whole SIM signal lines should be wrapped with GND as a group at
least.
The filter capacitors and ESD devices for SIM card signals should be placed near to the SIM card slot,
and the ESD devices with 22-33pF capacitance should be used.
3.6
Status Indicator
The L860 module provides two signals to indicate the operating status of the module, and the status
indicator pins are shown in the following table:
Pin
Pin Name
I/O
Reset Value Pin Description
Type
10
LED1#
O
T
System status LED, drain output.
3.3V
23
WOWWAN#
O
PD
Module wakes up Host (AP), reserved
1.8V
LED#1 Signal
The LED#1 signal is used to indicate the operating status of the module, and the detailed description is
shown in the following table:
Module Status
LED1# Signal
RF function ON
Low level (LED on)
RF function OFF
High level (LED off)
Fibocom
Confidential