TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R07
Advance Information
Design-in
Page 121 of 158
2.9.1.2
Guidelines for LED_WWAN# circuit design
As described in Figure 69 and Table 44, 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 69: LED_WWAN# application circuit
Reference
Description
Remarks
DL
LED Green SMT 0603
LTST-C190KGKT - Lite-on Technology Corporation
R
470
Resistor 0402 5% 0.1 W
Various manufacturers
Table 44: 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.
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 Figure 70.
TOBY-L2 series
RSVD
6
RSVD
Figure 70: Application circuit for the reserved pins (RSVD)