1.0
Overview
This Chapter provides a detailed theory of operation for the power distribution and controller circuits
in the radio. The components for these circuits are contained on the Main Board. Refer to the RF
sections of this manual for the component location details and the parts lists for these circuits.
2.0
Radio Power Distribution
UNSWB+
Fuse
7.5V
Battery
MECH.
SWB+
3.5V
Reg.
LI Ion
Low Battery
PA, Driver
PCIC(ALC)
Figure 1-1 illustrates the DC distribution throughout the radio board. A 7.5V battery (BATT 7.5V)
supplies power directly to the electronic on/off control as UNSWB+. When the radio is turned on,
MECH_SWB+ (on/off/volume control) will trigger the electronic on/off control (momentary-on path),
then SWB+ is distributed as shown in Figure1-1. Vdda from 3.3V Vdda regulator will then supply the
microprocessor. Data is then sent to ASFIC_CMP to turn on GCB4(DAC). GCB4 will take over the
momentary-on path within 12ms. SWB+ will continue to support the whole board until the radio is
turned off.
Radio will be turned-off on two conditions;
1. MECH_SWB+ turned off
2. Low battery
When low battery level is detected by the microprocessor through both conditions above, it will store
the radio personality data to EEPROM before turning off.
All manuals and user guides at all-guidesbox.com
Audio PA
4.0V/3.3V
Vdda
Reg.
R5
R2
SWB+
R1
Vddd
Reg.
TX.
Led
Control
On/Off Switch
Detect
Ant. SW
RF. AMP, IF AMP
Ext. RX.
Buffer (NU)
Figure 1-1 DC Power Distribution Block Diagram
THEORY OF OPERATION
Accessories
20 pin Connector
Keypad/Option Board
Prime Expansion Board
Switching
Reg.
Int/Ext Vdd
R4
Vdda
R3
Vddd
LCD
ASFIC_CMP
MCU Micro P, ROM
Driver
& EEPROM
5V
Reg.
5V
Dual Vdd
Jumpers
Regulator
Scheme
R1
R2
R3
R4
R5
Vdda
SW. Reg.
Chapter 1
FRACTN
IF
VCOBIC
Single Vdd
Regulator
Scheme
Y
Y
N
N
N
Y
N
N
Y
N
Y
N
N
N
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