Chapter 2 Dc Power Distribution; Dc Regulation And Distribution; Figure 2-1. Dc Power Distribution Block Diagram - Motorola CP150 Service Manual

Chapter 2 DC Power Distribution

2.1

DC Regulation and Distribution

A block diagram of the DC power distribution throughout the radio is shown in
UNSWB+
7.5V
Battery
Fuse
MECH.
SWB+
3.3V
Reg.
Low Battery
LI Ion
Detect
PA, Driver
PCIC(ALC)
Battery voltage enters at connector J301 and is routed through fuse F301 to become USWB+.
VR301 protects against ESD, and D301 provides reverse polarity protection. This voltage is routed
to:
• FET switch Q170 in the TX power control circuit (turned on during transmit)
• TX power amplifier module U110 (via R150)
• input pins of regulators U310, U320 and U330
• FET switch Q493 (turned on whenever the radio is on)
• on-off switch S444 (part of on-off-volume control) to become SWB+
Audio
Power
Amplifier
Vdda
Regulator
SWB+
Vddd
Regulator
Tx
Control
Led
On/Off
Switch
Antenna
Switch

Figure 2-1. DC Power Distribution Block Diagram

Keypad/Option Board
Vdda
Vddd
MCU, ROM LCD
and EEPROM Driver
5V
Regulator
5V
RF AMP, IF AMP,
RX/TX Buffers
Figure 2-1.
Accessories
20 pin Connector
FRACTN
ASFIC_CMP
VCOBIC
IFIC