Maxim Integrated MAX2769 GPS Receiver User Manual
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LNA1)
EV kit)
IF Output Gain
Range (4.092MHz
IF)
27–18
J6 or J7–J2
55dB to 110dB
3dB IF Filter
Passband
27–18
J7–J2
2.5MHz (default)
4MHz Offset Filter
Rejection
18
J7–J2
29dB (3rd-order BPF), 48dB (5th-
order BPF)
Digital Output
25, 27–17, 18, 20, 21
J12–J9
CMOS square wave with 50% duty
cycle
AGC Function
25, 27–17, 18, 20, 21
J12–J9
Flat, -105dBm to -65dBm input
Suggested Test Procedures for Initial Device Characterization
U8 should be installed—make sure only U8 or Y2 is installed. The software assumes a reference frequency of 16.368MHz. If
another frequency is used, change PLLCONFIG<22:21>. On the EV kit, remove U28, R61, R62, R63, R64, R65, C68, and
C69. C26 should be installed, but U11 should not be installed on the board. For cascaded measurements, connect J8 to J12
using an RF cable.
For analog measurements (see steps 1 through 14 below), make certain that R47, R48, R52, and R54 have been inserted.
This connects the output path through the two (MAX4444) differential-to-single-ended line receivers to ports J3 (I out) and J2
(Q out) where measurements can be made. A 50Ω load (such as a cable to a spectrum analyzer) should be placed on the
ports for correct loading. (Note that baluns T2 and T3 are not required and should not be loaded.)
Jumpers should be set as follows:
Connect W1–W9.
Connect top two pins of W16, W17 (connecting signal paths) and W23, which shorts the signal to ground.
Do not connect W13–W15, W18, and W28 (note that W13–W15 set up preconfigured states and will disable SPI
commands).
LNA1 Tests (Default Current Mode)
1. Apply 3V, ±5V, and GND at W19, W20, W11, and W12.
2. Run the software to set up new default register configurations, as shown below and described in the appendix.
(Note that these are not the default values.)
Config1:
A2959A3
Config2:
85502AC
Config3:
EAFF1DC
PLL Config:
9EC0008
PLL Integer Division:
0C00080
PLL Fractional Division Ratio: 8000070
DSP Interface:
8000000
CLK Fractional Division Ratio: 10061B2
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