Theory of Operation: Global Positioning System (GPS) 3-73
.
Figure 3-56. GPS Block Diagram (UHF1/700–800 MHz,UHF1/VHF, UHF1/UHF2, UHF2/700–800 MHz, and
UHF2/VHF) – Expander Board MHLN6977
.
Figure 3-57. GPS Block Diagram (VHF/700–800 MHz, UHF1/700–800 MHz,UHF2/700–800 MHz, UHF1/VHF,
UHF2/VHF, and UHF1/UHF2) – Expander Board MHLN7035A
RF-Vocon-Exp
Interconnect
RF Board
Ant
LNA
3.0V
Unbalanced
SAW
Unbalanced
SAW
LNA
GPS_2.8V
LNA Enable
3.6V
(VSW_3.6)
2.8V 1.8V 1.2V
GPS_2.8V
[OMAP 1710]
UART2_Rx (R9)
RF Vcc I/O Vcc Core Vdd
UART2_Tx (M18)
IO74 (E2)
IO91 (D12)
FDOUT (H1)
RFA_INP (A5)
RFA_INM (B5)
REF_CLK_IN (D4)
MISO_TXD0 (J6)
MOSI_RXD0 (K6)
LOW_REF_CLKI (D1)
NRESET (C1)
SiRF GSCi-5001
GPS IC
Reset
32kHz RTC
GPS Rx
GPS Tx
TCXO
26MHz
<0.5ppm
External Regulators
Expansion Board
Balanced
SAW
LNA Enable
RF-Vocon-Exp
Interconnect
RF Board
Ant
LNA
Unbalanced
SAW
Unbalanced
SAW
LNA
2.8V
1.8V
3.6V
(VSW_36)
[OMAP 1710]
UART2_Rx (R9)
VBAT1
VDD
UART2_Tx (M18)
IO74 (E2)
IO91 (D12)
GPS_EXT_LNA_EN
GPS IC
TI NL5500
TCXO_CLK_LV
GPS_UART_TX
GPS_UART_RX
Reset
32kHz RTC
GPS Rx
GPS Tx
TCXO
26MHz
<0.5ppm
External Regulators
Expansion Board
Balanced
SAW
RTC_CLK
GPS_N_SHUTDOWN
3.0V