文档介绍：Service Manual
Service Manual
U250/KU250
Model : U250/KU250
Date: June, 2007 / Issue
Table Of Contents
1. INTRODUCTION .............................. 5 Receiver Path ....................................107
Purpose................................................... 5 Headset path......................................109
Regulatory Information............................ 5 Speaker phone path...........................111
Main microphone ...............................113
2. PERFORMANCE...............................7 Headset microphone..........................115
Vibrator ..............................................117
System Overview.....................................7
Usable environment.................................8
5. DOWNLOAD..................................119
Radio Performance..................................8
Current Consumption.............................14 U250/KU250 DOWNLOAD ..................119
RSSI BAR ..............................................14 Introduction ...................................119
Battery BAR ...........................................15 Downloading Procedure ...............119
Sound Pressure Level............................16 Troubleshooting Download Errors 129
Charging ................................................16 Caution .........................................133
3. TECHNICAL BRIEF ........................17 6. BLOCK DIAGRAM ........................134
General Description ...............................17 GSM & UMTS RF Block.......................134
GSM Mode.............................................19 Interface Diagram ................................136
UMTS Mode...........................................23
LO generation and distribution circuits...25 7. Circuit Diagram ............................143
Off-chip ponents ...............