max2659eltt Maxim Integrated Products, Inc., max2659eltt Datasheet - Page 5
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max2659eltt
Manufacturer Part Number
max2659eltt
Description
Max2659 Gps/gnss Low-noise Amplifier
Manufacturer
Maxim Integrated Products, Inc.
Datasheet
1.MAX2659ELTT.pdf
(7 pages)
Table 1. Typical S11 Values
The MAX2659 is an LNA designed for GPS L1,
GALILEO, and GLONASS applications. The device fea-
tures a power-shutdown control mode to eliminate the
need for an external supply switch. The device
achieves a 20.5dB gain and an ultra-low-noise figure of
0.8dB. The MAX2659 consumes approximately 4.1mA
while providing a IP
The MAX2659 requires an off-chip input matching. Only
a 6.8nH inductor in series with a DC-blocking capacitor
is needed to form the input matching circuit. The
Typical Application Circuit diagram shows the recom-
mended input-matching network. These values are
optimized for the best simultaneous gain, noise figure,
and return loss performance. Table 1 lists typical
device S11 values. The MAX2659 integrates an on-chip
output matching to 50Ω at the output, eliminating the
need for external matching components.
FREQUENCY (MHz)
PIN
1, 2
3
4
5
6
1000
1100
1200
1300
1400
1500
1575
1600
1700
1800
1900
2000
RFOUT
NAME
SHDN
RFIN
GND
V
CC
_______________________________________________________________________________________
1dB
Input and Output Matching
Detailed Description
Ground. Connect to the PCB ground plane.
RF Input. Requires a DC-blocking capacitor and external matching components.
Supply Voltage. Bypass to ground with a 33nF capacitor as close as possible to the IC.
Shutdown Input. A logic-low disables the device.
RF Output. RFOUT is internally matched to 50
of -12dBm and an IIP3 of -5dBm.
REAL S11
-0.676
-0.228
-0.58
-0.68
-0.74
-0.74
-0.56
-0.47
-0.44
-0.36
-0.14
-0.3
IMAGINARY S11
GPS/GNSS Low-Noise Amplifier
-j0.356
j0.036
j0.415
j0.467
j0.567
j0.622
-j0.52
-j0.16
j0.22
j0.36
j0.43
j0.51
The MAX2659 includes a shutdown feature to turn off
the entire chip. Apply a logic high to SHDN pin to place
the part in the active mode and a logic low to place the
part in the shutdown mode.
A properly designed PC board (PCB) is essential to any
RF microwave circuit. Use controlled-impedance lines
on all high-frequency inputs and outputs. Bypass V
with decoupling capacitors located close to the device.
For long V
pling capacitors. Locate these additional capacitors
further away from the device package. Proper ground-
ing of the GND pins is essential. If the PCB uses a top-
side RF ground, connect it directly to the GND pins. For
a board where the ground is not on the component
layer, connect the GND pins to the board with multiple
vias close to the package.
PROCESS: SiGe BiCMOS
FUNCTION
and incorporates an internal DC-blocking capacitor.
CC
lines, it may be necessary to add decou-
Applications Information
Chip Information
Pin Description
Shutdown
CC
5