TOBY-L1 and MPCI-L1 series - System Integration Manual
UBX-13001482 - R04
Advance Information
Design-in
Page 63 of 90
2.8.1.2
Guidelines for LED_WWAN# circuit design
As described in Figure 38 and Table 23, the MPCI-L1 series modules
LED_WWAN#
active-low open drain output
can be directly connected to a system-mounted LED to provide the Wireless Wide Area Network status indication
as specified by the
PCI Express Mini Card Electromechanical Specification
Open
Drain
Output
R
3V3
DL
42
LED_WWAN#
MPCI-L1 series
Figure 38: LED_WWAN# application circuit
Reference
Description
Remarks
DL
LED Green SMT 0603
LTST-C190KGKT - Lite-on Technology Corporation
R
470
Ω
Resistor 0402 5% 0.1 W
Various manufacturers
Table 23: Example of components for the LED_WWAN# application circuit
ESD sensitivity rating of the
LED_WWAN#
pin is 1 kV (Human Body Model according to JESD22-A114).
Higher protection level could be required if the line is externally accessible and it can be achieved by
mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor) close to accessible point.
If the
LED_WWAN#
functionality is not required by the application, the pin can be left unconnected.