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 24 of 188
1.5.1.3 VCC current consumption in 3G connected mode
During a 3G connection, the SARA-U2 modules can transmit and receive continuously due to the Frequency
Division Duplex (FDD) mode of operation with the Wideband Code Division Multiple Access (WCDMA).
The current consumption depends again on output RF power, which is always regulated by network commands.
These power control commands are logically divided into a slot of 666 µs, thus the rate of power change can
reach a maximum rate of 1.5 kHz.
There are no high current peaks as in the 2G connection, since transmission and reception are continuously
enabled due to FDD WCDMA implemented in the 3G that differs from the TDMA implemented in the 2G case.
In the worst scenario, corresponding to a continuous transmission and reception at maximum RF output power
(approximately 250 mW or 24 dBm), the average current drawn by the module at the VCC pins is high (see the
SARA-U2 series Data Sheet [2]). Even at lowest RF output power level (approximately 0.01 µW or -50 dBm), the
average current is still not so low as in the equivalent 2G case, also due to module continuous baseband
processing and transceiver activity.
Figure 10 shows an example of current consumption profile of SARA-U2 series modules in 3G WCDMA/HSPA
continuous transmission and reception mode. For detailed current consumption values during a 3G connection
see the SARA-U2 series Data Sheet [2].
Time
[ms]
3G frame
10 ms
(1 frame = 15 slots)
Current [mA]
Depends
on TX
power
170 mA
1 slot
666 µs
850 mA
0
300
200
100
500
400
600
700
800
Figure 10: VCC current consumption profile versus time during a 3G connection (TX and RX continuously enabled)