6871620L01-C
May 28, 2008
Radio Power:
General
2-1
Chapter 2 Radio Power
This chapter provides a detailed circuit description of the power distribution of an ASTRO XTS 4000
radio.
2.1
General
In the ASTRO XTS 4000 radio, power (B+) is distributed to two sections: the transceiver (RF) section
and the VOCON section (
)
Power for the radio is provided through a battery supplying a nominal 7.5 Vdc directly to the
mainboard. The following battery types and capacities are available:
Figure 2-1. DC Power Distribution – VHF/ UHF Radio
B+ from the battery is electrically switched to most of the radio. The electrical switching of B+
supports a
keep-alive
mode. Under software control, even when the radio is turned off, power
remains on until the MCU completes its power-down, at which time the radio is physically powered
down.
Table 2-1. Conventional Batteries
Part Number
Description
NNTN6944
630mAH Li-Ion Battery
BATTERY
7.5 Volts
(Nominal)
BATT
Fuse
RAW B+
(to XCVR)
XB+
FB+
5V_MISC
SW_B+
FET
V5A
FET
MAKO
V5R
V3D
V3A
5 Volts
5 Volts
Analog Circuits
SW_B+_
(control signal)
3.8V(VSW1)
VCC5
5 Volts
Digital
Circuits
V2
2.9 Volts
Digital
Circuits
1.55
Volts
Patriot
1.875
Volts
Patriot
5 Volts
3 Volts
RF Circuits
3 Volts
RF Circuits
Summary of Contents for ASTRO XTSTM 4000
Page 1: ...COLOR CHORDS 7 ASTRO XTSTM 4000 Portable Radio Detailed Service Manual ...
Page 2: ......
Page 16: ...May 28 2008 6871620L01 C xiv Commercial Warranty Notes ...
Page 22: ...May 28 2008 6871620L01 C 1 6 Introduction Notes ...
Page 26: ...May 28 2008 6871620L01 C 2 4 Radio Power Notes ...
Page 56: ...May 28 2008 6871620L01 C 3 30 Theory of Operation Notes ...
Page 100: ...May 28 2008 6871620L01 C 6 8 Troubleshooting Waveforms Notes ...
Page 194: ...May 28 2008 6871620L01 C B 2 Motorola Service Centers Notes ...
Page 204: ...May 28 2008 6871620L01 C Glossary 10 Glossary Notes ...
Page 209: ......