Product Info

5G Module Series

RM500Q-AE&RM502Q-AE Hardware Design

RM500Q-AE&RM502Q-AE_Hardware_Design 33 / 83

Module (U)SIM Card

Connector

USIM_DET

USIM_DATA

USIM_CLK

RST

CLK

USIM_VDD

USIM_RST

VCC

GND

VPP

GND

TVS

Note: All these resistors, capacitors and TVS should be close to (U)SIM card connector in PCB layout.

10-20k

22R

33 pF

100 nF

Figure 15: Reference Circuit for a 6-Pin (U)SIM Card Connector

To enhance the reliability and availability of the (U)SIM card in applications, please follow the criteria

below in (U)SIM circuit design.

⚫ Place the (U)SIM card connector as close to the module as possible. Keep the trace length less than

200 mm.

⚫ Keep (U)SIM card signals away from RF and VCC traces.

⚫ Make sure the ground between the module and the (U)SIM card connector is short and wide. Keep

the trace width of ground and USIM_VDD no less than 0.5 mm to maintain the same electric

potential.

⚫ To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and

shield them with surrounded ground.

⚫ To offer better ESD protection, add a TVS diode array of which the parasitic capacitance should be

not higher than 10 pF. Add 22 Ω resistors in series between the module and the (U)SIM card

connector to suppress EMI such as spurious transmission, and to enhance ESD protection. The 33

pF capacitors are used to filter out RF interference.

⚫ For USIM_DATA, a 10–20 kΩ pull-up resistor must be added near the (U)SIM card connector.

⚫ (U)SIM card hot-plug is disabled by default.

3.8. USB Interface

RM500Q-AE&RM502Q-AE module provides one integrated Universal Serial Bus (USB) interface which

complies with the USB 3.1 & 2.0 specifications and supports super speed (10) on USB 3.1 and high

speed (480 Mbps) and full speed (12 Mbps) modes on USB 2.0. The USB interface is used for AT

command communication, data transmission, GNSS NMEA sentence output, software debugging,

firmware upgrade.