TOBY-L4 series - System Integration Manual
UBX-16024839 - R04
System description
Page 10 of 143
1.2
Architecture
Figure 1 summarizes the internal architecture of the TOBY-L4 series modules.
Cellular
Base-band
Processor
Memory
Power Management Unit
26 MHz
32.768 kHz
ANT1
RF
Transceiver
ANT2
V_INT (I/O)
V_BCKP (RTC)
VCC (Supply)
2 x SIM
USB 2.0 / 3.0
2 x ADC
Power on
External reset
PAs
LNAs
Filters
Filters
Duplexer
Filters
PAs
LNAs
Filters
Filters
Duplexer
Filters
LNAs
Filters
Filters
LNAs
Filters
Filters
Switch
Switch
2 x DDC (I
2
C)
SDIO
4 x UART
Analog audio
Antenna detection
Host Select
2 x SPI
RGMII
eMCC
2 x Digital audio (I
2
S)
GPIOs
Figure 1: TOBY-L4 series modules simplified block diagram
TOBY-L4 series modules internally consist of the RF, Baseband and Power Management sections described herein
with more details than the simplified block diagrams of Figure 1.
RF section
The RF section is composed of an RF transceiver, PAs, LNAs, crystal oscillator, filters, duplexers and RF switches.
The Tx signal is pre-amplified by the RF transceiver, then output to the primary antenna input/output port
(
ANT1
) of the module via power amplifier (PA), SAW band pass filters band, specific duplexer and antenna
switch.
Dual receiving paths are implemented according to Carrier Aggregation, MIMO, and Receiver Diversity radio
technologies supported by the modules as LTE category 6 and HSDPA category 24 User Equipments: incoming
signals are received through the primary (
ANT1
) and the secondary (
ANT2
) antenna input ports which are
connected to the RF transceiver via specific antenna switch, diplexer, duplexer, LNA, SAW band pass filters.
RF transceiver performs modulation, up-conversion of the baseband I/O signals for Tx, down-conversion and
demodulation of the dual RF signals for Rx. The RF transceiver contains:
Single chain high linearity receivers with integrated LNAs for multi-band multi-mode CA operation,
Highly linear RF demodulator / modulator capable GMSK, 8-PSK, QPSK, 16-QAM, 64-QAM
RF synthesizer,
VCO.
Power Amplifiers (PA) amplify the Tx signal modulated by the RF transceiver
RF switches connect the primary (
ANT1
) and secondary (
ANT2
) antenna ports to the suitable Tx / Rx path
SAW duplexers and band pass filters separate the Tx and Rx signal paths and provide RF filtering
26 MHz voltage-controlled temperature-controlled crystal oscillator (VC-TCXO) generates the clock reference
in active mode or connected mode.
