Controller Circuits
1-3
The voltage VSTBY, which is derived directly from the supply voltage by components R0621 and
VR0621, is used to buffer the internal RAM. C0622 allows the battery voltage to be disconnected for
a couple of seconds without losing RAM parameters. Dual diode D0621 prevents radio circuitry from
discharging this capacitor. When the supply voltage is applied to the radio, C0622 is charged via
R0621 and D0621. To avoid that the µP enters the wrong mode when the radio is switched on while
the voltage across C0622 is still too low, the regulated 5V charges C0622 via diode D0621.
Figure 2-1
DC Power Distribution Block Diagram
The voltage INT SW B+ from switching transistor Q0661 provides power to the circuit controlling the
audio PA output. The voltage INT SW B+ voltage is monitored by the µP through voltage divider
R0671 / R0672 and line BATTERY VOLTAGE. Diode VR0671 limits the divided voltage to 5.6V to
protect the µP.
Regulator U0611 is used to generate the voltage for the switched supply voltage output (SWB+) at
the accessory connector J0501 pin 13. U0611 is configured to operate as a switch with voltage and
current limit. R0611 / R0612 set the maximum output voltage to 16.5 volts. This limitation is only
active at high supply voltage levels. The regulator output is electronically enabled by a 0 volt signal
on pin 2. Q0661, Q0641 and R0641 are used to disable the regulator when the radio is turned off.
Input and output capacitors (C0603 and C0611 / C0612) are used to reduce high frequency noise.
Diode VR0601 acts as protection against transients and wrong polarity of the supply voltage.
Fuse F0401 prevents damage of the board in case the FLT A+ line is shorted at the controlhead
connector.
1.4
Electronic ON/OFF
The radio has circuitry which allows radio software and/or external triggers to turn the radio on or off
without direct user action. For example, automatic turn on when ignition is sensed and off when
ignition is off.
Q0661 is used to provide INT SW B+ to the various radio circuits and to enable the voltage
regulators via transistor Q0641. Q0661 contains an pnp and an npn transistor and acts as an
electronic on/off switch. The switch is on when the collector of the npn transistor within Q0661 is low.
When the radio is off the collector is at supply voltage level. This effectively prevents current flow
VCOBIC
FRACTN
VSTBY
5V_RF
9V3
FLT_A+
5VD
SWB+
Option Board
40 Pin Connector
PA, Driver
Antenna Switch
Controlhead
12 Pin Connector
Accessories
20 Pin Connector
J0601
13.2V
PASUPVLTG
FLT_A+
16.5V
Limiter
ON / OFF
Control
ASFIC_CMP
5.6V
Ignition
Emergency
ON/OFF
9.3V
Regulator
Audio PA
6V
Regulator
5V
Regulator
5VD
5V
Regulator
5V/
VDDA
MCU
µP, RAM,
FLASH & EEPROM
PCIC,
TX Amp
Temp Sense
RX RF Amp
IF Amp
F0
40
1
Summary of Contents for 6864115B62-C
Page 1: ...Professional Radio GM Series Detailed Service Manual 6864115B62 C ...
Page 2: ...ii ...
Page 4: ...iv ...
Page 5: ...Professional Radio GM Series Service Maintainability Issue July 2007 ...
Page 8: ...ii ...
Page 22: ...2 10 MAINTENANCE ...
Page 25: ...Professional Radio GM Series Controlhead Service Information Issue July 2007 ...
Page 77: ...Professional Radio GM Series Controller Service Information Issue May 2007 ...
Page 100: ...2 2 TROUBLESHOOTING CHARTS ...
Page 104: ...3 4 Controller schematics parts list ...
Page 154: ...3 52 Controller T12 Schematic Diagrams ...
Page 155: ...Professional Radio GM Series VHF 136 174MHz Service Information Issue May 2007 ...
Page 164: ...1 6 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 176: ...2 12 THEORY OF OPERATION ...
Page 186: ...3 10 TROUBLESHOOTING CHARTS ...
Page 190: ...4 4 VHF PCB SCHEMATICS PARTS LISTS ...
Page 252: ...4 66 VHF 1 25W PCB 8471235L02 Schematics VHF 136 174 MHz IF ...
Page 256: ...4 70 VHF 1 25W PCB 8471235L02 Schematics ...
Page 257: ...Professional Radio GM Series UHF 403 470MHz Service Information Issue May 2007 ...
Page 266: ...1 6 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 366: ...2 12 THEORY OF OPERATION ...
Page 372: ...3 6 Low Band TROUBLESHOOTING CHARTS ...