Table of Contents v
68P81094C31-O April 15, 2002
4.2.3.1 Abacus III IC U500................................................................................................... 4-4
4.2.3.2 Second Local Oscillator ........................................................................................... 4-5
4.2.3.3 Sampling Clock Oscillator........................................................................................ 4-5
4.2.4 Transmitter........................................................................................................................ 4-5
4.2.4.1 Power Distribution.................................................................................................... 4-5
4.2.4.2 Driver Amplifier U102............................................................................................... 4-5
4.2.4.3 Power Amplifier Transistor Q107............................................................................. 4-5
4.2.4.4 Directional Coupler U101......................................................................................... 4-6
4.2.4.5 Antenna Switch........................................................................................................ 4-6
4.2.4.6 Harmonic Filter ........................................................................................................ 4-6
4.2.4.7 RF Detectors D101 and D102 ................................................................................. 4-6
4.2.4.8 Summing Amplifier U106 ......................................................................................... 4-6
4.2.4.9 Power-Control IC (PCIC) U104................................................................................ 4-7
4.2.5 Frequency Generation Unit (FGU).................................................................................... 4-9
4.2.5.1 Reference Oscillator Y200....................................................................................... 4-9
4.2.5.2 Fractional-N Frequency Synthesizer (FracN) IC U202 ............................................ 4-9
4.2.5.3 Loop Filter..............................................................................................................4-10
4.2.5.4 VCO Buffer IC (VCOBIC) U300 ............................................................................. 4-10
4.3 VOCON Board ............................................................................................................................. 4-11
4.3.1 Interconnections ............................................................................................................. 4-11
4.3.1.1 Universal Connector J101 ..................................................................................... 4-12
4.3.1.2 Encryption Connector J701 ................................................................................... 4-12
4.3.1.3 Keypad Module Connector P107........................................................................... 4-12
4.3.1.4 RF Interface Connector P201 ................................................................................ 4-12
4.3.1.5 Display Module Connector P301 ........................................................................... 4-12
4.3.2 Controller and Memory Section ...................................................................................... 4-12
4.3.2.1 Patriot IC U401 ...................................................................................................... 4-13
4.3.2.2 Static RAM (SRAM) U403 ..................................................................................... 4-15
4.3.2.3 FLASH Memory U402............................................................................................ 4-15
4.3.3 Audio and Power Section ............................................................................................... 4-16
4.3.3.1 GCAP II IC U501 ................................................................................................... 4-17
4.3.3.2 5-Volt Regulator U505 ........................................................................................... 4-18
4.3.3.3 Audio Pre-Amplifier U502 ...................................................................................... 4-18
4.3.3.4 Audio Power Amplifier U503.................................................................................. 4-18
4.3.3.5 EEPOT U509 ......................................................................................................... 4-19
4.3.4 Interface Support Section ............................................................................................... 4-19
4.3.4.1 Flipper IC U301...................................................................................................... 4-19
4.3.4.2 ESD Protection Circuitry ........................................................................................ 4-21
4.3.4.3 Universal Connector Interface Circuitry ................................................................. 4-22
4.3.4.4 Display Module ...................................................................................................... 4-23
4.3.4.5 Keypad Module...................................................................................................... 4-23
4.3.4.6 Controls and Control Top Flex............................................................................... 4-24
4.3.4.7 System Clocks ....................................................................................................... 4-25
4.3.5 VOCON Audio Paths ...................................................................................................... 4-25
4.3.5.1 Transmit Audio Path .............................................................................................. 4-26
4.3.5.2 Receive Audio Path ............................................................................................... 4-27
4.3.6 Radio Power-Up/Power-Down Sequence....................................................................... 4-27
4.4 Encryption Module ....................................................................................................................... 4-28
Chapter 5 Troubleshooting Procedures ............................................. 5-1
5.1 Introduction .................................................................................................................................... 5-1
5.2 Handling Precautions..................................................................................................................... 5-1