TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R28
Design-in
Page 118 of 164
2.9.1.2
Guidelines for LED_WWAN# circuit design
As described in
, the MPCI-L2 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-L2 series
Figure 67: LED_WWAN# application circuit
Reference
Description
Part Number – Manufacturer
DL
LED Green SMT 0603
LTST-C190KGKT – Lite-on Technology Corporation
R
470
Resistor 0402 5% 0.1 W
Various manufacturers
Table 42: Example of components for the LED_WWAN# application circuit
☞
ESD sensitivity rating of the LED_WWAN# pin is 1 kV (HBM 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 LED_WWAN# functionality is not required by the application, the pin can be left unconnected.
2.9.1.3
Guidelines for W_DISABLE# and LED_WWAN# layout design
The W_DISABLE# and LED_WWAN# circuits are generally not critical for layout.
2.10
Reserved pins (RSVD)
☞
Pins reserved for future use, marked as RSVD, are not available on MPCI-L2 series.
TOBY-L2 series modules have pins reserved for future use. All the RSVD pins are to be left
unconnected on the application board except the RSVD pin number 6 which must be connected to
ground as described in
1:1 scaling
TOBY-L2 series
RSVD
6
RSVD
Figure 68: Application circuit for the reserved pins (RSVD)
