Theory of Operation
: Global Positioning System (GPS)
3-45
.
Figure 3-34. GPS Block Diagram
Table 3-9. Power and I/O Pins for NL5500
Signal Name
Type
NL5500 ball(s)
Source/Destination [ref] (board
Description
VBAT
Power
A2, H1, D8
VSW_3.6 [U6504] (
Main
Board)
Main NL5500 power supply
VDDS
Power
B3, G10, K5, E2
VCC_1.85 [U6508] (
Main
Board)
I/O Power Supply
VDD_TCXO
Power
G1
VSW_3.6 [U6504] (
Main
Board)
TCXO Power Supply
RTC_CLK
Clock
H9
CPLD IO74 [U6101] (
Main
Board)
32kHz RTC
TCXO_CLK_LV
Clock
F1
TCXO [Y1304] (
Main
Board)
26MHz TCXO
GPS_nShutdown
Input
D5
CPLD IO91 [U6101] (
Main
Board)
GPS Reset
GPS_UART_TX
Output
F5
OMAP pin R9 [U6302] (
Main
Board)
GPS UART TX to OMAP UART RX
GPS_UART_RX
Input
E3
OMAP pin M18 [U6302] (
Main
Board)
OMAP UART TX to GPS UART RX
LNA_ENABLE
Output
H6
LNA [U1304] (
Main
Board)
GPS External LNA Enable
GPS_LNA_IN
Input
L2
GPS antenna/front-end
GPS RF Input from antenna
GPS IC
TI NL5500
GPS_LNA_IN (L2)
GPS_EXT_LNA_EN (H6)
TCXO_CLK_LV (F1)
TCXO
26MHz,
<0.5ppm
GPS_UART_TX (F5)
GPS_UART_RX (E3)
UART2 Rx (R9)
UART2 Tx (M18)
[OMAP 1710]
GPS Tx
GPS Rx
GPS_NSHUTDOWN (D5)
RTC_CLK (H9)
32kHz RTC
[CPLD]
IO74 (E2)
IO91 (D12)
Reset
External Regulators
1.8V
(VCC_1.85)
2.8V
LNA Enable
LNA
Ant
Main Board
3.6V
(VSW_3.6)
SAW
SAW
VDD_TCXO (G1)
VBAT
VDDS
Summary of Contents for Astro APX 3000
Page 1: ...APXTM TWO WAY RADIOS APX 3000 DETAILED SERVICE MANUAL ...
Page 2: ......
Page 4: ...Notes ...
Page 6: ...vi Document History Notes ...
Page 10: ...x Table of Contents Notes ...
Page 12: ...xii List of Tables Notes ...
Page 18: ...xviii List of Figures Notes ...
Page 22: ...xxii CommercialWarranty Notes ...
Page 46: ...3 20 Theory of Operation Main Board Notes ...
Page 84: ...3 58 Theory of Operation Bluetooth Notes ...
Page 208: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Page 222: ...7 14 Troubleshooting Tables List of Board and IC Signals Notes ...
Page 282: ...8 60 Schematics Boards Overlays and Parts Lists Main Board Block UHF1 84012513001_A Notes ...
Page 390: ...8 168 Schematics Boards Overlays and Parts Lists Main Board Block VHF 84012512001_A Notes ...
Page 456: ...9 8 Debugging Fixture Powering up Covert Board Notes ...
Page 468: ...Glossary 10 Glossary Notes ...
Page 472: ...Index 4 Index Notes ...
Page 473: ......