User Guide

After Sales
Technical Documentation
System Module
THX–4
Amendment 10/97Page 4–2
CHAPTER 4 – SYSTEM MODULE
CONTENTS
Page No
Introduction 4–5
General 4–5
Special Features 4–5
Technical Specifications 4–5
Modes of Operation 4–5
External Signals and Connections 4–5
System Connector J1 4–6
Display Module Connector J2 4–7
Internal Signals 4–8
Connections between RF and Baseband 4–8
Functional Description 4–9
Logic Circuit Description 4–9
General 4–9
Micro–controller 4–9
Micro–controller D404 Pinout 4–9
Modem 4–11
Modem (N403) Signals 4–11
Regulators 4–11
PSL N407 Signals 4–12
Memories 4–12
EEPROM D406 Signals 4–12
Charging Control 4–13
Display Lighting 4–13
Audio Circuit Description 4–13
Transmit (TX) Signal Path 4–13
Receiver (RX) Signal Path 4–14
RF Circuit Description 4–15
Receiver Signal Path 4–15
Synthesizers 4–16
VCO’s and Buffers 4–16