Motorola XTS 2500 Service Manual page 9

Table of Contents
4.4.6.1.1 Patriot IC (U800)................................................................................................... 4.4-5
4.4.6.1.2 SRAM (U804) ....................................................................................................... 4.4-8
4.4.6.1.3 Flash Memory (U803) ........................................................................................... 4.4-8
4.4.6.2 Audio and Power Section ............................................................................................ 4.4-10
4.4.6.2.1 MAKO IC (U701)................................................................................................. 4.4-10
4.4.6.2.2 Regulator ............................................................................................................ 4.4-11
4.4.6.2.3 Audio Pre-Amplifier............................................................................................. 4.4-11
4.4.6.2.4 Audio Power Amplifier ........................................................................................ 4.4-11
4.4.6.3 Interface Support Section ............................................................................................ 4.4-12
4.4.6.3.1 MAKO IC U701 ................................................................................................... 4.4-12
4.4.6.3.2 ESD Protection Circuitry ..................................................................................... 4.4-13
4.4.6.3.3 Universal Connector (Side Connector) Interface Circuitry.................................. 4.4-13
4.4.6.3.4 The Option Board ............................................................................................... 4.4-15
4.4.6.3.5 Encryption Module .............................................................................................. 4.4-16
4.4.6.3.6 System Clocks .................................................................................................... 4.4-17
4.4.6.4 Transmit Audio Path .................................................................................................... 4.4-17
4.4.6.5 Receive Audio Path ..................................................................................................... 4.4-18
Chapter 4.5 900 MHz Detailed Theories of Operation ....................... 4.5-1
4.5.1 Introduction................................................................................................................................ 4.5-1
4.5.2 Frequency Synthesis................................................................................................................. 4.5-1
4.5.3 Antenna Switch ......................................................................................................................... 4.5-2
4.5.4 Receiver .................................................................................................................................... 4.5-3
4.5.4.1 Front End ....................................................................................................................... 4.5-3
4.5.4.2 Back End ....................................................................................................................... 4.5-4
4.5.5 Transmitter ................................................................................................................................ 4.5-4
4.5.6 VOCON Functional Blocks ........................................................................................................ 4.5-5
4.5.6.1 Controller and Memory Section ..................................................................................... 4.5-5
4.5.6.1.1 Patriot IC (U800)................................................................................................... 4.5-5
4.5.6.1.2 SRAM (U804) ....................................................................................................... 4.5-8
4.5.6.1.3 Flash Memory (U803) ........................................................................................... 4.5-8
4.5.6.2 Audio and Power Section ............................................................................................ 4.5-10
4.5.6.2.1 MAKO IC (U701)................................................................................................. 4.5-10
4.5.6.2.2 Regulator ............................................................................................................ 4.5-11
4.5.6.2.3 Audio Pre-Amplifier............................................................................................. 4.5-11
4.5.6.2.4 Audio Power Amplifier ........................................................................................ 4.5-11
4.5.6.3 Interface Support Section ............................................................................................ 4.5-11
4.5.6.3.1 MAKO IC U701 ................................................................................................... 4.5-12
4.5.6.3.2 ESD Protection Circuitry ..................................................................................... 4.5-13
4.5.6.3.3 Universal Connector (Side Connector) Interface Circuitry.................................. 4.5-13
4.5.6.3.4 The Option Board ............................................................................................... 4.5-14
4.5.6.3.5 Encryption Module .............................................................................................. 4.5-16
4.5.6.3.6 System Clocks .................................................................................................... 4.5-17
4.5.6.4 Transmit Audio Path .................................................................................................... 4.5-17
4.5.6.5 Receive Audio Path ..................................................................................................... 4.5-18
Chapter 5 Troubleshooting Procedures ............................................. 5-1
5.1 Introduction................................................................................................................................... 5-1
5.2 Handling Precautions ................................................................................................................... 5-1
5.3 Voltage Measurement and Signal Tracing ................................................................................... 5-1
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February 14, 2012