User's Manual
Table Of Contents
- Preface
- Contents
- 1 System description
- 1.1 Overview
- 1.2 Architecture
- 1.3 Pin-out
- 1.4 Operating modes
- 1.5 Supply interfaces
- 1.6 System function interfaces
- 1.7 Antenna interface
- 1.8 SIM interface
- 1.9 Serial interfaces
- 1.9.1 Asynchronous serial interface (UART)
- 1.9.1.1 UART features
- 1.9.1.2 UART AT interface configuration
- 1.9.1.3 UART signal behavior
- 1.9.1.4 UART and power-saving
- AT+UPSV=0: power saving disabled, fixed active-mode
- AT+UPSV=1: power saving enabled, cyclic idle/active-mode
- AT+UPSV=2: power saving enabled and controlled by the RTS line
- AT+UPSV=3: power saving enabled and controlled by the DTR line
- Wake up via data reception
- Additional considerations for SARA-U2 modules
- 1.9.1.5 Multiplexer protocol (3GPP 27.010)
- 1.9.2 Auxiliary asynchronous serial interface (UART AUX)
- 1.9.3 USB interface
- 1.9.4 DDC (I2C) interface
- 1.9.1 Asynchronous serial interface (UART)
- 1.10 Audio interface
- 1.11 General Purpose Input/Output (GPIO)
- 1.12 Reserved pins (RSVD)
- 1.13 System features
- 1.13.1 Network indication
- 1.13.2 Antenna detection
- 1.13.3 Jamming detection
- 1.13.4 TCP/IP and UDP/IP
- 1.13.5 FTP
- 1.13.6 HTTP
- 1.13.7 SMTP
- 1.13.8 SSL
- 1.13.9 Dual stack IPv4/IPv6
- 1.13.10 Smart temperature management
- 1.13.11 AssistNow clients and GNSS integration
- 1.13.12 Hybrid positioning and CellLocateTM
- 1.13.13 Firmware upgrade Over AT (FOAT)
- 1.13.14 Firmware upgrade Over The Air (FOTA)
- 1.13.15 In-Band modem (eCall / ERA-GLONASS)
- 1.13.16 SIM Access Profile (SAP)
- 1.13.17 Power saving
- 2 Design-in
- 2.1 Overview
- 2.2 Supply interfaces
- 2.2.1 Module supply (VCC)
- 2.2.1.1 General guidelines for VCC supply circuit selection and design
- 2.2.1.2 Guidelines for VCC supply circuit design using a switching regulator
- 2.2.1.3 Guidelines for VCC supply circuit design using a Low Drop-Out (LDO) linear regulator
- 2.2.1.4 Guidelines for VCC supply circuit design using a rechargeable Li-Ion or Li-Pol battery
- 2.2.1.5 Guidelines for VCC supply circuit design using a primary (disposable) battery
- 2.2.1.6 Additional guidelines for VCC supply circuit design
- 2.2.1.7 Guidelines for external battery charging circuit
- 2.2.1.8 Guidelines for external battery charging and power path management circuit
- 2.2.1.9 Guidelines for VCC supply layout design
- 2.2.1.10 Guidelines for grounding layout design
- 2.2.2 RTC supply (V_BCKP)
- 2.2.3 Interface supply (V_INT)
- 2.2.1 Module supply (VCC)
- 2.3 System functions interfaces
- 2.4 Antenna interface
- 2.5 SIM interface
- 2.6 Serial interfaces
- 2.6.1 Asynchronous serial interface (UART)
- 2.6.1.1 Guidelines for UART circuit design
- Providing the full RS-232 functionality (using the complete V.24 link)
- Providing the TXD, RXD, RTS, CTS and DTR lines only (not using the complete V.24 link)
- Providing the TXD, RXD, RTS and CTS lines only (not using the complete V.24 link)
- Providing the TXD and RXD lines only (not using the complete V24 link)
- Additional considerations
- 2.6.1.2 Guidelines for UART layout design
- 2.6.1.1 Guidelines for UART circuit design
- 2.6.2 Auxiliary asynchronous serial interface (UART AUX)
- 2.6.3 Universal Serial Bus (USB)
- 2.6.4 DDC (I2C) interface
- 2.6.1 Asynchronous serial interface (UART)
- 2.7 Audio interface
- 2.7.1 Analog audio interface
- 2.7.1.1 Guidelines for microphone and speaker connection circuit design (headset / handset modes)
- 2.7.1.2 Guidelines for microphone and loudspeaker connection circuit design (hands-free mode)
- 2.7.1.3 Guidelines for external analog audio device connection circuit design
- 2.7.1.4 Guidelines for analog audio layout design
- 2.7.2 Digital audio interface
- 2.7.1 Analog audio interface
- 2.8 General Purpose Input/Output (GPIO)
- 2.9 Reserved pins (RSVD)
- 2.10 Module placement
- 2.11 Module footprint and paste mask
- 2.12 Thermal guidelines
- 2.13 ESD guidelines
- 2.14 SARA-G350 ATEX integration in explosive atmospheres applications
- 2.15 Schematic for SARA-G3 and SARA-U2 series module integration
- 2.16 Design-in checklist
- 3 Handling and soldering
- 4 Approvals
- 5 Product testing
- Appendix
- A Migration between LISA and SARA-G3 modules
- A.1 Overview
- A.2 Checklist for migration
- A.3 Software migration
- A.4 Hardware migration
- B Migration between SARA-G3 and SARA-U2
- C Glossary
- Related documents
- Revision history
- Contact
SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R08 Objective Specification System description
Page 30 of 188
The RTC has very low power consumption, but is highly temperature dependent. For example at 25 °C, with the
V_BCKP voltage equal to the typical output value, the current consumption is approximately 2 µA (see the
“Input characteristics of Supply/Power pins” table in the SARA-G3 series Data Sheet [1] and SARA-U2 series Data
Sheet [2] for the detailed specification), whereas at 70 °C and an equal voltage the current consumption
increases to 5-10 µA.
If V_BCKP is left unconnected and the module main voltage supply is removed from VCC, the RTC is supplied
from the bypass capacitor mounted inside the module. However, this capacitor is not able to provide a long
buffering time: within few milliseconds the voltage on V_BCKP will go below the valid range (1 V min). This has
no impact on cellular connectivity, as all the module functionalities do not rely on date and time setting.
1.5.3 Generic digital interfaces supply output (V_INT)
The same 1.8 V voltage domain used internally to supply the generic digital interfaces of SARA-G3 and SARA-U2
series modules is also available on the V_INT supply output pin, as described in Figure 16.
Baseband
Processor
51
VCC
52
VCC
53
VCC
4
V_INT
Switching
Step-Down
Digital I/O
Interfaces
Power
Management
SARA-G3 / SARA-U2 series
Figure 16: SARA-G3 and SARA-U2 series interfaces supply output (V_INT) simplified block diagram
The internal regulator that generates the V_INT supply is a switching step-down converter that is directly
supplied from VCC. The voltage regulator output is set to 1.8 V (typical) when the module is switched on and it
is disabled when the module is switched off.
The switching regulator operates in Pulse Width Modulation (PWM) for greater efficiency at high output loads
when the module is in active-mode or in connected-mode. When the module is in low power idle-mode
between paging periods and with power saving configuration enabled by the appropriate AT command, it
automatically switches to Pulse Frequency Modulation (PFM) for greater efficiency at low output loads. See the
u-blox AT Commands Manual [3], +UPSV command.