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
Table 11: ADC specification
Parameter Min Typ Max Unit
Voltage range 0 - 2.8 V
ADC Resolution - 10 - bits
Sampling rate - - 200K Hz
4.11 RI Behaviours
Table 12: RI behaviours
State RI response
Standby High
Voice call
The pin is changed to low. When any of the following events occur, the pin will be changed
to high:
（1）Establish the call
（2）Hang up the call
Data call
The pin is changed to low. When any of the following events occur, the pin will be changed
to high:
（1）Establish the call
（2）Hang up the call
SMS
The pin is changed to low, and kept low for 120ms when a SMS is received. Then it is
changed to high.
The pin is changed to low, and kept low for 120ms when some URCs are reported. Then it is
changed to high. For more details, please refer to document [8].
URC
The behavior of the RI pin is shown in the following figure when the module is used as a receiver.
HIGH
LOW
Idle Ring
Hang up the call
Establish the call
RI
Figure 30: RI behaviour of voice calling as a receiver
HIGH
LOW
Idle Ring
Hang up the call
Establish the call
RI
Figure 31: RI behaviour of data calling as a receiver
SIM900R_Hardware Design_V1.00 32 2012-07-20