5G Module Series
RM502Q-GL Hardware Design
RM502Q-GL_Hardware_Design 36 / 77
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 of VCC_IO_HOST depends on the host side due to the open drain in pins
50, 52 and 54.
C6 220nF
C5 220nF
C2 220nF
C1 220nF
R1
100k
R2
100k
R3
100k
Figure 21: 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.
Figure 22: PCIe Power-on Timing Requirements of M.2 Specification