Only For Training And Service Purposes - LG CP150 Service Manual

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.
Copyright © 2008 LG Electronics. Inc. All right reserved.

Only for training and service purposes

3. HW Circuit Description
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LGE Internal Use Only