Samsung SGH-X460 Service Manual

Also see for SGH-X460: Manual

Contents

SAMSUNG Proprietary-Contents may change without noticeB. TX PARTBaseband IQ signal fed into offset PLL, this function is included inside of U100 chip.UAA3536 chip generates modulator signal which power level is about 1.5dBm and fed intoPower Amplifier(U105).The PA output power and power ramping are well controlled by Auto Power Control circuit.We use offset PLL below table.Modulation Spectrum200kHz offset30 kHz bandwidthGSM -35dBcDCS -35dBc400kHz offset30 kHz bandwidthGSM -66dBcDCS -65dBc600kHz ~ 1.8MHz offset30 kHz bandwidthGSM -75dBcDCS -68dBcA. PCF506011. Power ManagementTen low-dropout regulators designed specifically for GSM applications power the terminal andhelp ensure optimal system performance and long battery life. A programmable boost converterprovides support for 1.8V, 3.0V, and 5.0V SIMs, while a self-resetting, electronically fusedswitch supplies power to external accessories. Ancillary support functions, such as RTC moduleand High Voltage Charge pump, Clock generator, aid in reducing both board area and systemcomplexity.I2C BUS serial interface provides access to control and configuration registers. This interfacegives a microprocessor full control of the PCF50601 and enables system designers to maximizeboth standby and talk times.Supervisory functions. including a reset generator, an input voltage monitor, and a temperaturesensor, support reliable system design. These functions work together to ensure proper systembehavior during start-up or in the event of a fault condition(low microprocessor voltage,insufficient battery energy, or excessive die temperature).2. Backlight Brightness ModulatorThe Backlight Brightness Modulator (BBM) contains a programmable Pulse-width modulator(PWM) and FET to modulate the intensity of a series of LED’s or to control a DC/DCconverter that drives LCD backlight.This phone (SGH-X460) use PWM.