MAX2658EVKIT+ Maxim Integrated Products, MAX2658EVKIT+ Datasheet - Page 6

• Manufacturer Part Number: MAX2658EVKIT+
• Description: GPS/GNSS Low-Noise Amplifier Eval. Board
• Manufacturer: Maxim Integrated Products

Specifications of MAX2658EVKIT+

• Silicon Manufacturer: Maxim
• Peak Reflow Compatible (260 C): Yes
• Tool / Board Applications: Wireless Connectivity-ZigBee, RF, Infrared, USB
• Mcu Supported Families: MAX2658
• Development Tool Type: Hardware - Eval/Demo Board
• Leaded Process Compatible: Yes
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX2657/MAX2658 are LNAs designed for GPS
L1, Galileo, and GLONASS applications. The devices
feature a power-shutdown control mode to eliminate the
need for an external supply switch. The devices
achieve a high gain and an ultra-low-noise figure.
The MAX2657/MAX2658 require an off-chip input match-
ing. Only an inductor in series with a DC-blocking capac-
itor is needed to form the input matching circuit. The
Typical Application Circuit shows the recommended
input-matching network. These values are optimized for
the best simultaneous gain, noise figure, and return
loss performance. Tables 1 and 2 list typical device S
parameters and K
integrate an on-chip output matching to 50Ω at the out-
put, eliminating the need for external matching compo-
nents. The value of the input coupling capacitor affects
IIP3. A smaller coupling capacitor results in lower IIP3.
Table 1. MAX2657 Typical S-Parameter Values and K-Factor
GPS/GNSS Low-Noise Amplifiers
6
FREQ.
C1, C2
(MHz)
BUMP
1000
1100
1200
1300
1400
1500
1575
1600
1700
1800
1900
2000
_______________________________________________________________________________________
A1
A2
B1
B2
S11 MAG
(dB)
RFOUT
-2.0
-2.1
-2.2
-2.4
-2.7
-6.5
-4.3
-4.6
-5.4
-5.2
-4.8
-4.5
NAME
SHDN
RFIN
GND
V
CC
f
Input and Output Matching
values. The MAX2657/MAX2658
(Degrees)
Detailed Description
PHASE
Shutdown Input. A logic-low disables the device.
RF Output. RFOUT is internally matched to 50Ω and incorporates an internal DC-blocking capacitor.
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.
Ground. Connect to the PCB ground plane.
-47.7
-48.6
-51.6
-55.0
-58.6
-61.9
-62.3
-61.6
-55.3
-49.8
-47.3
-46.7
S11
S21 MAG
(dB)
12.0
14.0
16.2
17.1
17.3
17.1
15.7
13.9
12.7
6.0
7.4
9.6
(Degrees)
PHASE
-100.0
-100.6
-107.3
-117.2
-129.5
-146.5
-164.2
-170.6
165.5
145.8
135.2
127.3
S21
S12 MAG
-47.5
-45.7
-42.9
-39.6
-37.0
-34.1
-32.9
-32.8
-32.5
-33.8
-35.2
-36.7
The MAX2657/MAX2658 include a shutdown feature to
turn off the entire chip. Apply a logic-high to the 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 PCB is essential to any RF
microwave circuit. Use controlled-impedance lines on
all high-frequency inputs and outputs. Bypass V
decoupling capacitors located close to the device. For
long V
capacitors. Locate these additional capacitors further
away from the device package. Proper grounding of
the GND pins is essential. If the PCB uses a topside 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.
(dB)
FUNCTION
CC
lines, it may be necessary to add decoupling
(Degrees)
PHASE
-148.0
-150.0
-153.5
-160.2
-168.5
178.5
162.8
156.6
136.5
121.6
113.8
109.6
S12
Applications Information
S22 MAG
-15.3
-20.6
(dB)
-1.0
-1.0
-1.4
-2.1
-3.6
-7.4
-9.5
-4.5
-2.7
-1.8
Pin Description
(Degrees)
PHASE
-100.0
-100.8
-55.0
-58.1
-65.4
-74.1
-85.5
-78.9
-13.2
-21.2
10.0
S22
-2.4
Shutdown
CC
5.1
3.8
3.1
2.5
2.3
2.8
2.1
2.0
1.8
1.6
1.6
1.5
K
with
f