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CXA3329ER

Description of Operation

1. Outline of operation

This IC performs the signal processing between the analog transmit baseband processor block and the analog

transmit RF processor block of the cellular phone. The figure below shows the general circuit block diagram for

the portable cellular phones using this IC. The input for this IC is connected to the baseband signal processor

block; the output is connected to the analog RF processor block.

2. IC Internal Signal Flow

Two baseband-processed signals I, Q and the local signal are input to this IC as shown in the figure below.

The local signal is 1/2-frequency divided, and that signal becomes the quadrature I/Q local signal. The

baseband I/Q signals are input to the quadrature modulatar, and baseband processing to IF upconversion is

performed with the quadrature local signals. The signal is input to the gain control amplifier, and output after

the gain controlled to the necessary level.

RF receive/

transmit processor

Baseband signal

processor

CXA3328TN

CXA3329ER

1/2 div

(1/4 div)

–90˚

I/IX

Q/QX

OUT/OUTX

Local

0˚