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 47 / 90
shield them with surrounded ground.
⚫ To offer good ESD protection, it is recommended to add a TVS diode array of which the parasitic
capacitance should be less than 15 pF. Add 0 Ω resistors in series between the module and the
(U)SIM card to facilitate debugging. The 33 pF capacitors are used for filtering interference of
GSM900. Additionally, keep the (U)SI M peripheral circuit close to the (U)SIM card connector.
⚫ The pull-up resistor on USIM_DATA can improve anti-jamming capability of the (U)SIM card. If the
(U)SIM card traces are too long, or the interference source is relatively close, it is recommended to
add a pull-up resistor near the (U)SIM card connector.
4.5. I2C and PCM Interfaces
The module provides one I2C interface and one pulse code modulation (PCM) interface. The PCM
interface of the module only supports slave mode; therefore, the clock signal of the codec IC needs to be
provided externally.
Table 16: Pin Definition of I2C and PCM Interfaces
The following figure shows a reference design of I2C and PCM interfaces with an external codec IC.
Pin Name Pin No. I/O Description Comment
I2C_SCL 40 OD I2C serial clock
External pull-up resistor is required.
1.8 V power domain only.
If unused, keep them open.
I2C_SDA 41 OD I2C serial data
PCM_DIN 6 DI PCM data input
1.8 V power domain.
If unused, keep them open.
PCM_DOUT 7 DO PCM data output
PCM_SYNC 5 DI PCM data frame sync
PCM_CLK 4 DI PCM clock