Motorola GM950i

Theory of Operation 6.3-i
Chapter 6.3
Theory of Operation
Table of Contents
Table of Contents
Paragraph Page
1.0 Overview..................................................................................................... 1
2.0 Controller.................................................................................................... 2
2.1 General........................................................................................................ 2
2.2 Voltage Regulators ...................................................................................... 2
2.3 Electronic On/Off ......................................................................................... 3
2.4 Mechanical On/Off....................................................................................... 3
2.5 Ignition ......................................................................................................... 3
2.6 Hook ............................................................................................................ 4
2.7 Microprocessor Clock Synthesizer .............................................................. 4
2.8 Serial Peripheral Interface (SPI).................................................................. 4
2.9 SBEP Serial Interface.................................................................................. 5
2.10 General Purpose Input/Output..................................................................... 5
2.11 Normal Microprocessor Operation............................................................... 5
2.12 Control Head Model A2 or A3...................................................................... 6
Controller Board Audio and Signalling Circuits
3.0 General ....................................................................................................... 7
3.1 Audio Filter IC (AFIC) .................................................................................. 7
3.2 Audio Ground............................................................................................... 7
4.0 Transmit Audio Circuits............................................................................. 7
4.1 Mic Input Path.............................................................................................. 7
4.2 External Mic Path......................................................................................... 8
4.3 PTT Sensing and TX Audio Processing ...................................................... 8
4.4 Option Board only (GM950i only) ................................................................ 9
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