hardware design v1 00 2
Table Of Contents
- Contents
- Version History
- 1 Introduction
- 2 SIM900R Overview
- 3 Package Information
- 4 Application Interface
- 4.1 Power Supply
- 4.2 Power on/down Scenarios
- 4.3 Power Saving Mode
- 4.4 RTC Backup
- 4.5 Serial Interfaces
- 4.6 Audio Interfaces
- 4.7 SIM Card Interface
- 4.8 LCD Display/SPI Interface
- 4.9 Keypad Interface
- 4.10 ADC
- 4.11 RI Behaviours
- 4.12 Network Status Indication
- 4.13 General Purpose Input/Output (GPIO)
- 4.14 External Reset
- 4.15 PWM
- 4.16 I2C Bus
- 4.17 Antenna Interface
- 5 Electrical, Reliability and Radio Characteristics
- 5.1 Absolute Maximum Ratings
- 5.2 Recommended Operating Conditions
- 5.3 Digital Interface Characteristics
- 5.4 SIM Card Interface Characteristics
- 5.5 VDD_EXT Characteristics
- 5.6 SIM_VDD Characteristics
- 5.7 VRTC Characteristics
- 5.8 Current Consumption (VBAT = 3.8V)
- 5.9 Electro-Static Discharge
- 5.10 Radio Characteristics
- 6 Manufacturing
- Appendix
Smart Machine Smart Decision
4.7 SIM Card Interface
4.7.1 SIM Card Application
The SIM interface complies with the GSM Phase 1 specification and the new GSM Phase 2+ specification for
FAST 64 kbps SIM card. Both 1.8V and 3.0V SIM card are supported. The SIM interface is powered from an
internal regulator in the module.
It is recommended to use an ESD protection component such as ST (www.st.com
) ESDA6V1W5 or ON SEMI
(www.onsemi.com
) SMF05C.The pull up resistor (15KΩ) on the SIM_DATA line is already added in the module
internal. Note that the SIM peripheral circuit should be close to the SIM card socket. The reference circuit of the
8-pin SIM card holder is illustrated in the following figure.
Figure 25: Reference circuit of the 8-pin SIM card holder
The SIM_PRESENCE pin is used for detection of the SIM card hot plug in. User can select the 8-pin SIM card
holder to implement SIM card detection function. AT command “AT+CSDT” is used to enable or disable SIM
card detection function. For details of this AT command, please refer to document [1].
If the SIM card detection function is not used, user can keep the SIM_PRESENCE pin open. The reference
circuit of 6-pin SIM card holder is illustrated in the following figure.
Figure 26: Reference circuit of the 6-pin SIM card holder
SIM900R_Hardware Design_V1.00 28 2012-07-20