LG 410G Service Manual page 15

3. H/W Circuit Description
3.1.1 Overview of Locosto
The Locosto is a GSM base band modem including RF transceiver covering the low bands
GSM850 /GSM900 and high bands GSM1800 / GSM1900 bands. Locosto is Dual Band,
therefore, it supports by default a low / high pair of bands at the same time:
1. GSM850 / GSM1800
2. GSM850 / GSM1900
3. GSM900 / GSM1800
4. GSM900 / GSM1900
The Locosto is optimized for voice-centric Mobile Phone applications.
The Locosto is designed as a single chip solution that integrates the digital, mixed-signal, RF
functionality and a direct-to-battery Power Management Unit.
The transceiver consists of:
• Constant gain direct conversion receiver with an analog I/Q base band interface
• Fully integrated Sigma/Delta-synthesizer capability
• Fully integrated two-band RF oscillator
• Two-band digital GMSK modulator with digital TX interface
• Digitally controlled crystal oscillator generating system clocks.
The Locosto supports a direct battery connection, hence eliminating the need for an external
Power Management Unit. The Locosto has different power down modes and an integrated
power up sequencer.
The Locosto is powered by the ARM7(104MHz) MCU and C54® DSP cores.
The operating temperature range from -40°C to 85°C. It is manufactured using the 0.13 μm
CMOS process.
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