LTE-A Module Series
EM120R-GL&EM160R-GL Hardware Design
EM120R-GL&EM160R-GL_Hardware_Design 40 / 79
3.8.1. Endpoint Mode
EM120R-GL and EM160R-GL support endpoint (EP) mode. In this mode, the modules are configured as
a PCIe EP device. The following figure shows a reference circuit of PCIe endpoint mode.
Host
Module
PCIE_REFCLK_P
PCIE_REFCLK_M
PCIE_RX_P
PCIE_RX_M
PCIE_TX_P
PCIE_TX_M
BB
PCIE_REFCLK_P
PCIE_REFCLK_M
PCIE_RX_P
PCIE_RX_M
PCIE_TX_P
PCIE_TX_M
55
53
49
47
43
41
PCIE_CLKREQ_N
PCIE_RST_N
PCIE_WAKE_N
PCIE_CLKREQ_N
PCIE_RST_N
PCIE_WAKE_N
VCC_IO_HOST
54
52
50
Note:
The voltage level VCC_IO_HOST depends on the host side due to open drain in pin 50, 52
and 54.
C6 100 nF
C5 100 nF
C2 100 nF
C1 100 nF
R1
10K
R2
10K
R3
10K
Figure 22: PCIe Interface Reference Circuit (EP Mode)
In order to ensure the signal integrity of PCIe interface, AC coupling capacitors C5 and C6 should be
placed close to the host on PCB. C1 and C2 have been integrated inside the module, so do not place
these two capacitors on customers’ schematic and PCB.