Detailed Description
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
1dB
of -12dBm and an IIP3 of -5dBm.
Input and Output Matching
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.
Shutdown
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.
Applications Information
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
CC
with decoupling capacitors located close to the device.
For long V
CC
lines, it may be necessary to add decou-
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.
Chip Information
PROCESS: SiGe BiCMOS
MAX2659
GPS/GNSS Low-Noise Amplifier
_______________________________________________________________________________________ 5
Pin Description
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages
. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
6 µDFN L611+2
21-0147 90-0084
