G310 Service Manual
PANTECH
R&D
CONFIDENTIAL
13
transmit and RF voltage controlled oscillator (VCO) modules, and more than 60 other discrete
components found in conventional designs.
The receive section uses a digital low-IF architecture that avoids the difficulties associated with
direct conversion while delivering lower solution cost and reduced complexity. The universal
baseband interface (Z710) is compatible with any supplier’s baseband subsystem.
The transmit section is a complete up-conversion path from the baseband subsystem to the power
amplifer (Z710) and uses an offset phase locked loop (PLL) with a fully integrated transmit VCO.
The frequency synthesizer (U601) includes integrated RF and IF VCO’s, Varactors, and Loop filters.
The unique integer-N PLL architecture used in the Si4133T (U601) produces a transient response
that is superior in speed to fractional architectures without suffering the high phase noise or
spurious modulation effects often associated with those designs.
4.2.1 DC Distribution and Regulation Part
The 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 part
efficiently. Audio/Logic parts use +2.8V. RF parts such as U702(Si4201 universal baseband
interface), U710(Si4200 GSM Transceiver) and U601(Si4133T Dual RF synthesizer) also use
+2.8V DC voltage.
