Pantech G310 Service Manual

Pantech G310 Service Manual Manual pdf 22 page image

G310 Service ManualPANTECH R&D CONFIDENTIAL214.2.5 Offset PLL4.2.5.1 An Overview of Offset PLLFig.4-10. Si4133T Frequency Synthesizer Block DiagramThe Si4133T dual frequency systhesizer is a monolithic CMOS integrated circuit that performs IFand RF synthesis. Two complete PLLs are integrated including VCOs, varactors, resonators, loopfilters, reference and VCO dividers, and phase detectors. Differential outputs for the IF and RFPLLs are provided for direct connection to the Si4200 transceiver IC. The RF PLL uses twomultiplexed VCOs. The RF1 VCO is used for Receive mode, and RF2 VCO is used for Transmitmode. The IF PLL is used only during Transmit mode and uses a single VCO.The frequency synthesizer uses VC-TCXO(13MHz) as reference frequency. 13MHz of VC-TCXO issent to the frequency synthesizer as a reference input.