Pantech PG-1210 Service Manual

Also see for PG-1210: User manual

Pantech PG-1210 Service Manual Manual pdf 14 page image

PG-1210 Service ManualWhile conventional solutions use SiGe, BiCMOS, or other bipolar process technologies, the Aero IItransceiver is Silicon Laboratories' third-generation transceiver to be implemented in a 100% CMOSprocess. Silicon Laboratories’ focus on RF and analog mixed-signal CMOS design creates innovationin integration, space savings, and fabrication cost. This further extends the cost savings andextensive manufacturing capacity of CMOS to the GSM/GPRS market.4.2.1 DC Distribution and Regulation PartThe battery voltage, in return, is applied to the logic part and RF part via LDO(Low Drop-Out)regulator. As several LDO regulators are used, power can be supplied for each necessary partefficiently. Audio/Logic parts use +2.8V. Si4210 RF Transceiver also use +2.8V DC voltage.SKY77325 Power Amplifier (U505) use battery voltage.4.2.3 Receiver Section4.2.3.1 An Overview of Receive sectionFig.4-6. Receiver block diagramThe PG-1210’s Aero II transceiver uses a digital low-IF receiver architecture that allows for theon-chip integration of the channel selection filters, eliminating the external RF image reject filters, andthe IF SAW filter required in conventional superheterodyne architectures. Compared withdirect-conversion architectures, the digital low-IF architecture has a much greater degree of immunityto dc offsets that can arise from RF local oscillator (RFLO) self-mixing, second-order distortion ofblockers (AM suppression), and device 1/f noise.The digital low-IF receiver's immunity to dc offsets has the benefit of expanding part selection andimproving manufacturing. At the front end, the common-mode balance requirements on the inputSAW filters are relaxed, and the PCB board design is simplified. At the radio's opposite end, the BBICis one of the handset's largest BOM contributors. It is not uncommon for a direct conversion solution13PANTECH