19-1759; Rev 0; 7/00
MAX2645 Evaluation Kit
General Description
The MAX2645 evaluation kit (EV kit) simplifies evalua-
tion of the MAX2645 3.4GHz to 3.8GHz low-noise
amplifier/PA predriver. The EV kit is fully assembled
and tested, allowing simple evaluation of all device
functions. All RF signal ports use SMA connectors, pro-
viding a convenient interface to RF test equipment.
The MAX2645 is a versatile, high-performance, low-
noise amplifier with adjustable IP3. These features allow
the MAX2645 to be used in a variety of applications,
from a low-noise amplifier to a PA predriver. As assem-
bled, the MAX2645 EV kit is configured for lowest noise
figure performance (NF = 2.3dB, IIP3 = +4dBm). A few
minor component changes configure the device as a
low-noise amplifier with higher linearity and slightly
degraded noise figure performance (NF = 2.6dB, IIP3 =
+10dBm) or as a PA predriver with high output P1dB
performance (output P1dB = +12dBm). Refer to the
MAX2645 data sheet for application-specific perfor-
mance data.
o
Easy Evaluation of the MAX2645
o
All Critical Peripheral Components Included
o
SMA Input and Output Connectors
o
RF Ports Matched to 50Ω at 3.55GHz
o
Fully Assembled and Tested
Features
Evaluates: MAX2645
Ordering Information
PART
MAX2645EVKIT
*Exposed paddle
TEMP. RANGE
-40°C to +85°C
IC PACKAGE
10 µMAX-EP*
Component Suppliers
SUPPLIER
AVX
EFJohnson
Kamaya
Murata
Taiyo Yuden
Toko
PHONE
FAX
WEB
Avxcorp.com
843-448-9411 843-448-1943
402-474-4800 402-474-4858 Efjohnson.com
219-489-1533 219-489-2261 Kamaya.com
800-831-9172 814-238-0490
800-348-2496 847-925-0899
800-PIK-TOKO 708-699-1194
Murata.com
T-Yuden.com
Tokoam.com
Component List
DESIGNATION QTY
C1
C2
C3
C4
C5, C6, C8
C7
C9
Z1
1
1
1
1
3
1
1
1
DESCRIPTION
1.5pF
±0.1p
F ceramic capacitor (0402)
Murata GRM36COG1R5B050
220pF ±10% ceramic capacitor (0402)
Murata GRM36X7R221K050
47pF ±5% ceramic capacitor (0402)
Murata GRM36COG470J050
0.75pF
±0.1pF
ceramic capacitor
(0402) Murata GRM36COGR75B050
0.1µF ±10% ceramic capacitors
(0603) Murata GRM39X7R104K016
10µF, 16V tantalum capacitor
AVX TAJC106K016
1000pF ±10% ceramic capacitor
(0402) Murata GRM36X7R102K050
1.8nH inductor
Toko LL1005-FH1N8S
DESIGNATION QTY
R1
R2, R3
JU1, JU2
None
J1, J2
J3, J4
U1
None
None
None
1
2
2
2
2
2
1
1
1
1
DESCRIPTION
20kΩ ±1% resistor (0603)
1kΩ ±5% resistors (0603)
3-pin headers
Shunts (JU1, JU2)
Test points (VCC, GND)
SMA connectors (edge mount)
EFJohnson 142-0701-801
MAX2645EUB
MAX2645 PC board (GETek)
MAX2645 data sheet
MAX2645 EV kit data sheet
________________________________________________________________
Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX2645 Evaluation Kit
Evaluates: MAX2645
Test Equipment Required
This section lists the test equipment required for evalu-
ating the MAX2645:
•
One DC power supply capable of supplying 20mA
of supply current over the supply voltage range
+3.0V to +5.5V
One RF-signal generator or equivalent (50Ω) sine-
wave source capable of delivering at least -10dBm
of output power up to 3.8GHz (HP 8648, for exam-
ple)
One RF-spectrum analyzer or equivalent with a
frequency range of at least 4GHz (HP 8561E, for
example)
Two 50Ω SMA cables (RG-58A/U or equivalent)
Optional: Digital multimeters (DMMs) to monitor DC
supply voltage and supply current
•
Optional: Power meter for calibrating system mea-
surements (HP 438A for example)
Connections and Setup
This section provides step-by-step instructions for set-
ting up the EV kit and ensuring proper operation:
1)
DC Power Supply:
Set the DC power supply volt-
age to +3.3V. Turn the power supply off and con-
nect it to the VCC and GND connections on the EV
kit. If desired, place an ammeter in series with the
power supply to measure supply current and a volt-
meter in parallel with the VCC and GND connec-
tions to measure supply voltage at the device.
2)
RF Signal Generator:
Connect one of the 50Ω
SMA cables to the RF output of the signal genera-
tor. Set the RF frequency of the signal generator to
3.55GHz at an output power level of -20dBm. To
improve measurement accuracy, use a power
•
•
•
•
1
GND
V
CC
C3
47pF
R3
1k
C8
0.1µF
C6
0.1µF
V
CC
1
GAIN
0
JU1
VCC
C10
10µF
2
GND
GAIN
9
MAX2645
RFIN
C1
3
RFIN
SHDN
8
R2
1k
C8
0.1µF
1
SHDN
0
JU2
Z1
4
GND
GND
7
RADIAL STUB
*
40°
294
T
LINE
mil
s
L
EQUIV
= 1.5nH
5
C2
220pF
R1
BIAS
RFOUT
8
VCC
C9
1000pF
RFOUT
C4
0.75pF
APPLICATION CIRCUIT
LNA, LOW NF
LNA, HIGH INPUT IP3
PA PREDRIVER
C1
1.5pF
1000pF
0.01µF
Z1
1.8nH
0.75pF
0.75pF
R
BIAS
(kΩ) V
CC
(V)
20
3.3
20
15
3.3
5.0
*
BOARD MATERIAL = GETek, COPPER THICKNESS = 1 oz
BOARD THICKNESS = 0.012in, DIELECTRIC CONSTANT = 3.8
Figure 1. MAX2645 EV Kit Schematic
2
_______________________________________________________________________________________
MAX2645 Evaluation Kit
meter to measure the actual power at the end of the
SMA connector. Turn the output of the signal gen-
erator off once the output power has been set.
Connect the other end of the SMA cable to the
RFIN port of the MAX2645 EV kit.
3)
Spectrum Analyzer:
Connect the spectrum analyz-
er to the RFOUT port of the MAX2645 EV kit using a
50Ω SMA cable. Set the center frequency of the
spectrum analyzer to 3.55GHz, the frequency span
to 1MHz, and the reference level to 0dBm. To
improve measurement accuracy, calibrate out any
cable losses and spectrum analyzer offsets.
4)
Jumper Connections:
To enable the MAX2645,
connect the
SHDN
jumper (JU2) on the EV kit to the
“1” position (SHDN = V
CC
). To place the MAX2645
in high-gain mode, connect the GAIN jumper (JU1)
on the EV kit to the “1” position (GAIN = V
CC
).
To evaluate the MAX2645 low-power shutdown mode,
connect the
SHDN
jumper (JU2) on the EV kit to the “0”
position (SHDN = GND). The ammeter should read
approximately 0.1µA.
To evaluate the MAX2645 as a low-noise amplifier with
higher linearity performance or as a PA predriver,
replace capacitor C1, Z1, and resistor R1 with the com-
ponents recommended in the EV kit schematic (Figure
1). Refer to the MAX2645 data sheet for application-
specific performance data.
Evaluates: MAX2645
Layout and Bypassing
The MAX2645 RFOUT output port requires an equiva-
lent 1.5nH of high-impedance transmission line to V
CC
for proper biasing and matching. This transmission line
is terminated at the VCC node with a radial stub for
high-frequency bypassing. This arrangement provides
a high-Q, low-loss bias network used to optimize per-
formance. The radial stub can be replaced with an
appropriate microwave capacitor.
Good PC board layout is an essential aspect of RF cir-
cuit design. The MAX2645 EV board can serve as a
guide for layout of your board. Keep PC board trace
lengths as short as possible to minimize parasitics and
losses. Keep bypass capacitors as close to the device
as possible with low-inductance connections to the
ground plane. Refer to the MAX2645 data sheet for
more information regarding bypassing.
Analysis
Turn on the power supply, then the RF signal genera-
tor. The ammeter should read approximately 9.2mA,
and the spectrum analyzer should show an output
power of approximately -6dBm in high-gain mode. Be
sure to take into account cable and board losses when
calculating power gain. Typical board losses are 0.5dB
at 3.5GHz.
To evaluate the MAX2645 in low-gain mode, connect
the GAIN jumper (JU1) on the EV kit to the “0” position
(GAIN = GND). The ammeter should read approximate-
ly 3mA, and the spectrum analyzer should show an out-
put power of approximately -31dBm in low-gain mode.
1.0"
Figure 2. MAX2645 EV Kit PC Board Layout—Component
Placement Guide
1.0"
Figure 3. MAX2645 EV Kit PC Board Layout—Component Side
_______________________________________________________________________________________
3
MAX2645 Evaluation Kit
Evaluates: MAX2645
1.0"
Figure 4. MAX2645 EV Kit PC Board Layout—Ground Plane
1.0"
Figure 5. MAX2645 EV Kit PC Board Layout—Power Plane
1.0"
Figure 6. MAX2645 EV Kit PC Board Layout—Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2000 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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