Installation Instructions

LISA-U2 series - System Integration Manual
UBX-13001118 - R19 Early Production Information System description
Page 10 of 175
 Power Management Unit with integrated DC/DC converter for the Power Amplifier Module
 Voltage Controlled Temperature Compensated 26 MHz Crystal Oscillator (VC-TCXO)
While operating in 3G mode, the RF transceiver performs direct up-conversion and down-conversion of the
baseband I/Q signals, with the RF voltage controlled gain amplifier being used to set the uplink TX power. In the
downlink path, the integrated LNA enhances the RX sensitivity while discrete inter-stage SAW filters additionally
improve the rejection of out-of-band blockers. An internal programmable gain amplifier optimizes the signal
levels before delivering to the analog I/Q to baseband for further digital processing.
For 2G operations, a constant gain direct conversion receiver with integrated LNAs and highly linear RF
quadrature demodulator are used to provide the same I/Q signals to the baseband as well. In transmission mode,
the up-conversion is implemented by means of a digital sigma-delta transmitter or polar modulator depending
on the modulation to be transmitted.
The RF antenna pad for the diversity receiver (ANT_DIV) available on LISA-U230 modules is directly connected to
the antenna switch for the diversity receiver, which dispatches the incoming RF signals to the dedicated SAW
filter bank for out-of-band rejection and then to the diversity receiver port of the RF transceiver.
In all the modes, a fractional-N sigma-delta RF synthesizer and an on-chip 3.296-4.340 GHz voltage controlled
oscillator are used to generate the local oscillator signal. The frequency reference to RF oscillators is provided by
the 26 MHz VC-TCXO. The same signal is buffered to the baseband as a master reference for clock generation
circuits while operating in active mode.
LISA-U2 series modulation techniques
Modulation techniques related to radio technologies supported by LISA-U2 modules, are listed as follows:
 GSM  GMSK
 GPRS  GMSK
 EDGE  GMSK / 8-PSK
 WCDMA  QPSK
 HSDPA  QPSK / 16-QAM
 HSUPA  QPSK / 16-QAM
LISA-U2 series Baseband and Power Management Unit section
Another shielding box of LISA-U2 modules includes all the digital circuitry and the power supplies, basically the
following functional blocks:
 Cellular baseband processor, a mixed signal ASIC which integrates:
 Microprocessor for controller functions, 2G & 3G upper layer software
 DSP core for 2G Layer 1 and audio processing
 3G coprocessor and HW accelerator for 3G Layer 1 control software and routines
 Dedicated HW for interfaces management
 Memory system in a Multi-Chip Package (MCP) integrating two devices:
 NOR flash non-volatile memory
 DDR SRAM volatile memory
 Power Management Unit (PMU), used to derive all the system supply voltages from the module supply VCC
 32.768 kHz crystal, connected to the Real Time Clock (RTC) oscillator to provide the clock reference in idle or
power-off mode