Motorola Cleartone CM5000 Basic Service Manual page 28

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These signals are connected to the Microphone connector on the Key/Display unit and the interface
connector (J902) at the rear of the main units.
Transmit Audio Signal
TX audio, Ext. Mic of the external analog interface and Microphone signal of the Key/Display unit is
selected by the audio switch (IC806). SOC selects those signals. The selected signal is adjusted the
level by (IC802) and fed to the Linear CODEC in the AFE.
Power Supply Circuit
DC power for the radio is connected to the DC connector (J851) at the rear of the main unit. DC
power is divided to the un-switched pass and switched pass.
Not switched pass is connected to the voltage regulators (IC851 and IC852). The voltage regulators
supply DC power for the backup memory.
Switched pass is connected to the FET switch (TR851). This FET is controlled ON/OFF by the con-
trol signal that activated by the encoder on the Key/display unit or external device. ON/OFF control
signal is fed to the Gate of the FET via transistor (TR852 to TR855). The switched power is named
as SWA+. This power is connected to the followed voltage regulators.
IC853 and peripheral circuit consists of DC/DC converter and generate 3.3 V. This power is used for
the digital circuit such as SOC. And this power is connected to the followed voltage regulators to
generate lower voltage.
IC854 generates 1.8 V (1.8 VC), IC855 generates 2.5 V (2.5 VID) and IC856 generates 2.5 V
(2.5 VIA). Those regulators are designed to turn on in the order of 2.5 VIA, 2.5 VID and 1.8 VC.
IC857 generates 1.8 V (1.8 VI).
The reset IC (IC861) generates reset signal for SOC.
SIM Interface
The GSM type SIM card is used. SIM card is inserted to the SIM card connector (J801).
SIM interface IC (IC809) is used for the interface to the SOC.
GPS
GPS receiver (IC611) is used for receiving the GPS signal. External GPS antenna is connected to
the GPS antenna connector at the rear of the main unit. The GPS signal from the GPS antenna is
connected to the GPS receiver via the RF connector (J605).
The GPS receiver is connected via the serial interface IC (IC612) to the SOC. Received GPS signal
from the receiver or control signal from SOC is communicated by the serial communication.
DC power supply for the GPS antenna is feed through the J605.
RTC
The RTC (Real Time Clock) is controlled by the SOC via IIC bus. Also the RTC signal is outputted to
the SOC via IIC bus.
CM5000 Mobile Repeater/Gateway - Basic Service Manual OVERVIEW