Samsung SCH-i830 Service Manual

Also see for SCH-i830 Series: User guide Phone guide Pocket guide User guide Service manual

SAMSUNG Proprietary-Contents may change without noticeRx Audio PathThe PCM data from the MSM(UCP800)'s internal is inputted to the internal CODEC and the data will bedecoded by the internal DAC and audio levels are adjusted by the amplifier. The final audio is then sentto the audio receiver.2-2. PCS Section2-2-1. ReceiverLOW NOISE AMPLIFIER (U1000)The low noise amplifier(It is included in FC7510:U1000) amplifies a weak signal received fromthe base station to obtain the optimum signal level.RF BAND PASS FILTER (F1001)The RF BPF(F1001) passes only a specific frequency(1960±30 MHz) from the signal received from themobile station. The bandwidth is 60 MHz.VOLTAGE CONTROLLED OSCILLATOR(VCO1000)The VCO(VCO1000) generates the signal having center frequency 1715 ~ 1788MHz frequencyrange with the voltage control. The PLL in RTR6300(U1102) controls this signal.Frequency Synthesizer CircuitThe PLL(Phased Locked Loop) block consists of VC-TCXO(TCX1001), PLL in RTR6300 andVCO(VCO1000). Input reference frequency is generated at VC-TCXO(TCX1001) and the RFlocal signal is generated at VCO. PLL compares the two signals and generates the desiredsignal with a preprogrammed counter which controls voltage.VOLTAGE CONTROLLED TEMPERATURE COMPENSATED CRYSTAL OSCILLATOR (TCX1001)The VC-TCXO (TCX1001) is a reference source of the frequency synthesizer. It provides 19.2MHzreference frequency to PLL-IC. It is a voltage controlled temperature compensated crystaloscillator having 19.2MHz ±2.5ppm frequency stability over all useful temperature range.A correct frequency tuning is made by the control voltage.l