SARA-G3 series - System Integration Manual
UBX-13000995 - R06
Objective Specification
System description
Page 15 of 218
1.2.1
Internal blocks
SARA-G3 modules consist of the following internal sections: RF, Baseband and Power Management.
RF section
The RF section is composed of the following main elements:
RF transceiver performing modulation, up-conversion of the baseband I/Q signals, down-conversion and
demodulation of the RF received signals. The RF transceiver includes:
Constant gain direct conversion receiver with integrated LNAs
Highly linear RF quadrature GMSK demodulator
Digital Sigma-Delta transmitter GMSK modulator
Fractional-N Sigma-Delta RF synthesizer
3.8 GHz VCO
Digital controlled crystal oscillator
Transmit module, which amplifies the signals modulated by the RF transceiver and connects the single
antenna input/output pin (
ANT
) of the module to the suitable RX/TX path, via its integrated parts:
Power amplifier
Antenna switch
RX diplexer SAW (band pass) filters
26 MHz crystal, connected to the digital controlled crystal oscillator to perform the clock reference in
active-mode or connected-mode
Baseband and Power Management section
The Baseband and Power Management section is composed of the following main elements:
Baseband processor, a mixed signal ASIC which integrates:
Microprocessor for controller functions
DSP core for GSM/GPRS Layer 1 and audio processing
Dedicated peripheral blocks for parallel control of the digital interfaces
Audio analog front-end
Memory system in a multi-chip package integrating two devices:
NOR flash non-volatile memory
PSRAM volatile memory
Voltage regulators to derive all the system supply voltages from the module supply
VCC
SARA-G350 modules have an internal 32.768 kHz crystal connected to the oscillator of the RTC (Real
Time Clock) block that gives the RTC clock reference needed to provide the RTC functions as well as to
reach the very low power idle-mode (with power saving configuration enabled by the AT+UPSV
command).
SARA-G300 and SARA-G310 modules do not have an internal 32.768 kHz crystal: a proper 32 kHz
signal must be provided at the
EXT32K
input pin of the modules to give the RTC clock reference and to
provide the RTC functions as well as to reach the very low power idle-mode (with power saving
configuration enabled by the AT+UPSV command). The
32K_OUT
output pin of SARA-G300 and SARA-