Service Guide
Table Of Contents
- Safety Information
- About the Document
- Contents
- Table Index
- Figure Index
- 1 Introduction
- 2 Product Overview
- 3 Operating Characteristics
- 4 Application Interfaces
- 5 Antenna Interfaces
- 6 Reliability, Radio, and Electrical Characteristics
- 7 Mechanical Information
- 8 Storage, Manufacturing, and Packaging
- 9 Appendix References
LTE Standard Module Series
EG915U_Series_Hardware_Design 46 / 90
Module
USIM_VDD
GND
USIM_RST
USIM_CLK
USIM_DATA
USIM1_DET
0R
0R
0R
VDD_EXT
51K
100 nF
GND
GND
33 pF 33 pF 33 pF
VCC
RST
CLK
IO
VPP
GND
GND
USIM_VDD
15K
(U)SIM Card Connector
Switch
Figure 21: Reference Circuit of (U)SIM Interface with an 8-pin (U)SIM Card Connector
If (U)SIM card detection function is not needed, please keep USIM1_DET unconnected. A reference
circuit for (U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following figure.
Module
USIM_VDD
GND
USIM_RST
USIM_CLK
USIM_DATA
0R
0R
0R
100 nF
GND
33 pF 33 pF
33 pF
VCC
RST
CLK IO
VPP
GND
GND
15K
USIM_VDD
(U)SIM Card Connector
Figure 22: Reference Circuit of (U)SIM Interface with a 6-pin (U)SIM Card Connector
To enhance the reliability and availability of the (U)SIM card in applications, follow the criteria below in
(U)SIM circuit design:
⚫ Place (U)SIM card connector as close to the module as possible. Keep the trace length as short as
possible, at most 200 mm.
⚫ Keep (U)SIM card signals away from RF and VBAT traces.
⚫ Ensure the bypass capacitor between USIM_VDD and GND is less than 1 µF, and the capacitor
should be close to the (U)SIM card connector.
⚫ To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and