Controller Information; Overview; Radio Power Distribution - Motorola GP328 Plus Service Manual

Section 4

CONTROLLER INFORMATION

1.0

Overview

This section provides a detailed theory of operation for the radio and its components.
2.0

Radio Power Distribution

UNSWB+
Fuse
7.5V
Battery
3.5V
Reg.
LI Ion
PA, Driver
PCIC(ALC)
*Not applicable to GP328 Plus
Figure 4-1 illustrates the DC distribution throughout the radio board. A 7.5V battery (BATT 7.5V)
supplies power directly to the electronic ON/OFFcontrol as UNSWB+. When the radio is turned on,
MECH_SWB+ (ON/OFF volume control) will trigger the electronic ON/OFFcontrol(momentary-on
path), then SWB+ is distributed as shown in Figure 4-1. 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
Audio PA
R5
SWB+ R1
Control
MECH.
SWB+
On/Off Switch
Low Battery
Detect
Ant. SW
Figure 4-1: DC Power Distribution Block Diagram
Vdda
Vdda
Reg.
R3
R2
Vddd Vddd
Reg.
TX.
Led
* LCD
MCU Micro P, ROM
Driver
& EEPROM
5V
Reg.
5V
Jumpers
R1
RF. AMP, IF AMP
Ext. RX. R2
Buffer (NU)
R3
R4
R5
Vdda
SW. Reg.
FRACTN
ASFIC_CMP
LVZIF
VCOBIC
Dual Vdd Single Vdd
Regulator Regulator
Scheme Scheme
Y Y
N N
N Y
N N
Y N
Y N
N N
4-1