hardware design v1.00
Table Of Contents
- Contents
- Version History
- 1 Introduction
- 2 SIM968 Overview
- 3 Package Information
- 4 GSM Application Interface
- 4.1 GSM Power Supply
- 4.2 Power on/down Scenarios
- 4.3 Power Saving Mode
- 4.4 Charging Interface
- 4.5 RTC Backup
- 4.6 Serial Interfaces
- 4.7 Audio Interfaces
- 4.8 SIM Card Interface
- 4.9 LCD Display/SPI Interface
- 4.10 Keypad Interface
- 4.11 ADC
- 4.12 RI Behaviors
- 4.13 Network Status Indication
- 4.14 General Purpose Input/Output (GPIO)
- 4.15 External Reset
- 4.16 PWM
- 4.17 I2C Bus
- 4.18 GSM Antenna Interface
- 5 GNSS Application Interface
- 6 Electrical, Reliability and Radio Characteristics
- 6.1 Absolute Maximum Ratings
- 6.2 Recommended Operating Conditions
- 6.3 Digital Interface Characteristics
- 6.4 SIM Card Interface Characteristics
- 6.5 VDD_EXT Characteristics
- 6.6 SIM_VDD Characteristics
- 6.7 VRTC Characteristics
- 6.8 Current Consumption (VBAT = 3.8V)
- 6.9 Electro-Static Discharge
- 6.10 Radio Characteristics
- 6.11 Module label information
- Appendix
Smart Machine Smart Decision
SIM968_Hardware Design_V1.00 2013.02.25
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4.3 Power Saving Mode
SIM968 have two sleep modes: sleep mode 1 is enabled by hardware pin DTR; sleep mode 2 is only enabled by
serial port regardless of the DTR. In sleep mode, the current of module is very low. The AT command
“AT+CFUN=<fun>” can be used to set SIM968 into minimum functionality. When SIM968 is in sleep mode and
minimum functionality, the current of module is lowest.
4.3.1 Minimum Functionality Mode
There are three functionality modes, which could be set by the AT command “AT+CFUN=<fun>”. The command
provides the choice of the functionality levels <fun>=0,1,4.
z AT+CFUN=0: minimum functionality.
z AT+CFUN=1: full functionality (default).
z AT+CFUN=4: flight mode (disable RF function).
Minimum functionality mode minimizes the current consumption to the lowest level. If SIM968 is set to
minimum functionality by “AT+CFUN=0”, the RF function and SIM card function will be disabled. In this case,
the serial port is still accessible, but all AT commands correlative with RF function and SIM card function will not
be accessible.
For detailed information about the AT Command “AT+CFUN=<fun>”, please refer to document [1].
Table 6: The current consumption of Minimum Functionality Mode
<fun> Current consumption(uA) (sleep mode)
0 651
1 1500
4 715
4.3.2 Sleep Mode 1 (AT+CSCLK=1)
User can control SIM968 module to enter or exit the sleep mode 1 (AT+CSCLK=1) by DTR signal. When DTR is
in high level and without interrupt (on air and hardware such as GPIO interrupt or data in serial port), SIM968
will enter sleep mode 1 automatically. In this mode, SIM968 can still receive paging or SMS from network but the
serial port is not accessible.
Note: For SIM968, it requests to set AT command “AT+CSCLK=1” and ensure DTR at high level to enable the sleep mode 1; the
default value is 0, which can not make the module to enter sleep mode. For more details please refer to document [1].
4.3.3 Wake Up SIM968 from Sleep Mode 1 (AT+CSCLK=1)
When SIM968 is in sleep mode 1 (AT+CSCLK=1), the following methods can wake up the module:
z Pull down DTR pin.
The serial port will be active after DTR pin is pulled to low level for about 50ms.