Nokia 9000i, Service Manual

Page: 31 / 434

After Sales
Technical Documentation
RAE/RAK–1N
Baseband
Page 2–5
Original, 08/96
Introduction
The baseband engine consists of two multi chip modules (MCM) mounted
along with other baseband circuitry and RF parts on a single multilayer
PCB. The chassis of the radio unit has separating walls between
baseband and RF. All components are surface mounted. Transceiver
GE8 is GSM; Tranceiver GE9 is PCN
The connection to the NOKIA 9000 communicator PDA module is made
using a board to board connector. The connections to the User Interface
module (UIF) are made through the ‘passive’ PDA module. Besides the
PDA board to board connector only the SIM/audio and battery connector
are on the baseband module. There is no physical connector between the
RF and baseband sections.
Technical Summary
Because of extreme size constraints on this product new production
technology will be used. Most of the baseband ICs will be integrated in
two multi chip modules. These MCMs and all other baseband circuits are
mounted on a single multilayer printed circuit board. This board contains
also RF parts. The chassis of the radio unit has separating walls between
baseband and RF. All components of the baseband section including the
MCMs are surface mountable. They are soldered using reflow. The
connection to Responder PDA module is made using a board to board
connector. The connections to the User Interface module (UIF) are made
through the PDA module. Besides the PDA board to board connector only
the SIM/audio connector and battery connector are on the baseband
module. There is no physical connector between the RF and baseband
sections.
Table 1. List of Functional Submodules
Name of submodule Function
CTRLU Control Unit for phone
PWRU Power supply and charging electronics
DSPU Digital Signal Processing block
AUDIO Analog audio processing and PCM encoding/decoding
ASIC D2CA GSM/PCN system specific ASIC; several functions
RFI RF – baseband interface (analog signals)
The above blocks are only functional blocks and therefore have no type or
material codes. Physically the baseband contains two submodules, MCM1
and MCM2 which utilise COB (chip on board) packaging technology. The
MCM 1 contains the 7 ICs in the CTRLU submodule plus bypass
capacitors and some resistors.