Nokia 2270, 2272, 2275, 2285 Service Manual
CCS Technical Documentation
System Module
RH-3
Issue 1 06/2003
Nokia Corporation Confidential
Page 29
The RX IF ASIC Yoda is used to convert the IF down to baseband I and Q. The ASIC con-
tains a VGA section, IQ demodulator, and baseband filters (BBFIL) for CDMA. Switchable
gain baseband amplifier (BBAMP), and RX VHF PLL. The I/Q BB signals are output to UEM
chip for analog-to-digital conversion and further signal processing.
tains a VGA section, IQ demodulator, and baseband filters (BBFIL) for CDMA. Switchable
gain baseband amplifier (BBAMP), and RX VHF PLL. The I/Q BB signals are output to UEM
chip for analog-to-digital conversion and further signal processing.
GPS Engine
Introduction
Figure 15: GPS Engine Block Diagram
The GPS engine (GE) major components consist of two ASICs, the RF Front End with a
Low Noise Amplifier (LNA), a voltage regulator, and a Temperature-Controlled Crystal
Oscillator (TCXO). The front end provides filtering of out-of-band signals and amplifica-
tion of the frequency band of interest. The RF ASIC provides further amplification, AGC,
down-conversion to low IF, IF filtering and analog-to-digital conversion of the IF. The
baseband ASIC is responsible for all baseband processing of the GPS signal, including PN
wipeoff, decoding, and GPS measurement calculations. The TCXO provides a 16.368 MHz
signal for down-conversion and sampling and is used by the baseband ASIC for all the
GPS processing. The RF regulator provides voltage regulation from the battery to provide
2.8 volts for the RF components.
Low Noise Amplifier (LNA), a voltage regulator, and a Temperature-Controlled Crystal
Oscillator (TCXO). The front end provides filtering of out-of-band signals and amplifica-
tion of the frequency band of interest. The RF ASIC provides further amplification, AGC,
down-conversion to low IF, IF filtering and analog-to-digital conversion of the IF. The
baseband ASIC is responsible for all baseband processing of the GPS signal, including PN
wipeoff, decoding, and GPS measurement calculations. The TCXO provides a 16.368 MHz
signal for down-conversion and sampling and is used by the baseband ASIC for all the
GPS processing. The RF regulator provides voltage regulation from the battery to provide
2.8 volts for the RF components.
The GE is controlled by the Cellular Engine (CE) via the GE/CE Interface. When the CE
powers up, the GE performs a self-test and informs the CE of self-test results. If the self-
test results pass, the CE will download the operational code to the GE via the GE/CE
interface. If the self-test of the GE fails, the CE will declare a hardware failure and incre-
ment the “Test Mode 0 Failure” PPC. The CE will receive a GPS status message from the
GE after download as to the success of the download. If the download fails, the CE will
powers up, the GE performs a self-test and informs the CE of self-test results. If the self-
test results pass, the CE will download the operational code to the GE via the GE/CE
interface. If the self-test of the GE fails, the CE will declare a hardware failure and incre-
ment the “Test Mode 0 Failure” PPC. The CE will receive a GPS status message from the
GE after download as to the success of the download. If the download fails, the CE will
16.368 MHz
TC XO
BPF
Pr ogramming
Interface
Loo p
Fi l ter
Image Reject
Mixe r
LO=1571.328 MHz
÷ 2
AGC
V CO
T ank
Oscillator
÷ 2
÷ 8
÷12
P ha s e
Det
4
4 B i t
A DC
4.092MHz
D AT A
C LO CK
EN AB LE
fcom p=16.368MHz
IF out Tes t
Poi nts
L O /8 T e st Poi nt
19 6 .4 16 M Hz
ADCout
IFout
GPS Clo ck
LO/8 Test
SPI
LNA
SAW
15 75 .42 M Hz