November 16, 2006
6881094C31-E
3-12
Theory of Operation:
Transceiver Board
3.1.3.9.1 Power and Control
Since U104 is powered from switched B+, it makes its own regulated 4.5 Vdc to power the internal
logic. The supply input is V5EXT at pin 17, and the output is V45 at pin 16. RX at pin 23 is the control
signal to the antenna switch control circuit.
3.1.3.9.2 Voltage Multiplier
The PCIC contains an internal voltage multiplier. This multiplier produces signal V10 (pin 14), a 10-V
supply for the PCIC D/A converters (DACs). This enables the DACs outputs to reach 8 V. The FREF
signal is a 2.1 MHz clock used to switch the multiplier. The voltage multiplier is not used in either the
VHF, UHF Range 1, UHF Range 2, or 700–800 MHz radio.
3.1.3.9.3 Automatic Level Control (ALC)
In TX mode, the PCIC disables the receiver, turns on the transmitter, and controls the TX power
level. The automatic level control (ALC) circuit operates as follows:
9
F168
Reference clock input, 2.1 MHz
10, 13
QX, CQX
External capacitor for voltage multiplier
11, 12
Q, CQ
External capacitor for voltage multiplier
14
V10
Voltage multiplier output
15
VG
Internal band-gap reference voltage
16
V45
Regulated 4.5 Vdc output
17
V5EXT
Power supply input for internal voltage regulator
18
VAR2
Buffered D/A output
19
VLIM
Test point for internal D/A No.2 voltage
20
VAR1
Buffered D/A output
21
RS
Asynchronous reset input
22
NA
Spare pin
23
RX
RX/TX mode control-bit output
24
VAR3
Buffered D/A output
25
GND2
Ground
26
CLK
SPI clock input
27
BPOS
Power supply input
28
DATA
SPI data input/output
29
CEX
SPI chip select input
30
TEMP
Temperature sensor input
31
RSET
External resistor; used to set the temperature cutback rate
32
ANO
Switched BPOS output
Table 3-3. Power Control IC (U104) Pin Descriptions (Continued)
Pin
Name
Description
Summary of Contents for ASTRO XTS-5000
Page 7: ...vi Table of Contents November 16 2006 6881094C31 E Notes ...
Page 11: ...x List of Figures November 16 2006 6881094C31 E Notes ...
Page 17: ...November 16 2006 6881094C31 E xvi CommercialWarranty Notes ...
Page 31: ...November 16 2006 6881094C31 E xxx Portable Radio Model Numbering System Notes ...
Page 83: ...November 16 2006 6881094C31 E 3 44 Theory of Operation Encryption Module ...
Page 135: ...November 16 2006 6881094C31 E 5 44 Troubleshooting Charts Secure Hardware Failure Notes ...
Page 175: ...November 16 2006 6881094C31 E 7 32 Troubleshooting Tables List of Board and IC Signals Notes ...
Page 367: ...November 16 2006 6881094C31 E Glossary 10 Notes ...
Page 373: ...Index 6 November 16 2006 6881094C31 E Notes ...