19-1773; Rev 1; 11/00
MAX2251 Evaluation Kit
General Description
The MAX2251 evaluation kit (EV kit) simplifies evaluation
of the MAX2251 power amplifier (PA), which is designed
for operation in IS-136-based TDMA and AMPS. The kit
enables testing of the device’s RF performance and
requires no additional support circuitry. The EV kit’s signal
input and output use SMA connectors to facilitate the
connection of RF test equipment.
Each kit is assembled with the MAX2251 and incorpo-
rates input and output matching components optimized
for the 824MHz to 849MHz RF frequency band. The EV kit
is capable of operating at RF frequencies from 750MHz to
1000MHz with the appropriate matching components.
o
Easy Evaluation of MAX2251
o
+2.8V to +4.5V Single-Supply Operation
o
RF Input/Output Matched for 824MHz to 849MHz
Operation
o
Fully Assembled and Tested
Features
Evaluates: MAX2251
Ordering Information
PART
MAX2251EVKIT
TEMP. RANGE
-40°C to +85°C
IC PACKAGE
4
✕
4 UCSP
MAX2251 EV Kit Component List
DESIGNATION
QTY
DESCRIPTION
4.7µF
±20%,
10V tantalum cap
AVX TAJ A 475 M010 (10V A case)
AVX TAJ A 475 M020 (20V A case)
(A or B case PC board pads)
9pF
±0.5pF
ceramic cap (0402)
Murata GRM36COG090D050 or
Taiyo Yuden UMK105CH090DW
0.01µF
±10%
ceramic caps (0402)
Murata GRM36X7R103K016 or
Taiyo Yuden EMK105BJ103KV
100pF
±5%
ceramic caps (0402)
Murata GRM36COG101J050 or
Taiyo Yuden UMK105CH101JW
4700pF
±10%
ceramic cap (0402)
Murata GRM36X7R472K025 or
Taiyo Yuden TMK105B472KW
10pF
±1%
porcelain capacitor
ATC 100A100FW150X
220pF
±10%
ceramic cap
Murata GRM36COG221K050
4.7pF
±0.25pF
ceramic cap (0402)
Murata GRM36COG4R7C050
Taiyo Yuden EVK105CH4R7JW
DESIGNATION
C15
L1
L2
L3
R1, R2
R3
R4
B1
JU1, JU2
None
RFIN, RFOUT
V
CC
, GND, TP1
U1
QTY
1
1
1
1
2
1
1
1
2
2
2
3
1
DESCRIPTION
Do not install
4.7nH
±5%
inductor (0402)
Murata LQG10A4N7S00
7.15nH
±5%
air core inductor
Coilcraft 1606-7
Do not install
10kΩ
±5%
resistors (0402)
47.5kΩ
±1%
resistor (0603)
11kΩ
±1%
resistor (0603)
Ferrite bead
Murata BLM11P300SPT
3-pin headers
Shunts (JU1, JU2)
SMA connectors (PC edge mount)
EFJohnson 142-0701-801
Digi-Key J502-ND
Test points, Mouser 151-203
MAX2251E/B (16 CSP)
C1
1
C3
1
C4, C7, C10
3
C5, C6, C11
3
C9
1
C12
C13
1
1
C14
1
________________________________________________________________
Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX2251 Evaluation Kit
Evaluates: MAX2251
Component Suppliers
SUPPLIER
ATC
AVX
Coilcraft
EFJohnson
Kamaya
Murata Electronics
NEC
ROHM
Taiyo Yuden
PHONE
516-622-4700
803-946-0690
847-639-6400
402-474-4800
219-489-1533
800-831-9172
408-243-2111
408-433-2225
408-573-4150
FAX
516-622-4748
803-626-3123
847-639-1469
402-474-4858
219-489-2261
814-238-0490
408-243-2410
408-434-0531
408-573-4159
WEB
www.atceramics.com
www.avx-corp.com
www.coilcraft.com
www.efjohnson.com
www.kamaya.com
www.murata.com
www.cel.com
www.rohm.com
www.t-yuden.com
_________________________Quick Start
The MAX2251 EV kit is fully assembled and factory test-
ed. Follow the instructions in the
Connections and Setup
section for proper device evaluation.
Connections and Setup
This section provides a step-by-step guide to operating
the EV kit and testing the device’s functions. Do not
turn on the DC power or RF signal generator until all
connections are made:
1) Connect a 20dB high-power attenuator to the
RFOUT SMA connector on the EV kit. This will pre-
vent overloading the power sensor and the power
meter.
2) Connect a DC supply set to +3.3V (through an
ammeter, if desired), and connect the voltmeter to
the EV kit’s VCC and GND terminals.
3) Connect an RFIN signal generator to the RFIN SMA
connector. Set the generator for an 836MHz output
frequency at a 0dBm power level.
4) Connect the power sensor to the power meter.
Calibrate the power sensor for 836MHz. Set the
power meter offset to compensate the 20dB attenu-
ator plus any cable loss (between 0.5dB and 2dB).
5) Connect a power sensor to the 20dB high-power
attenuator.
6) Place the MODE jumper (JU1) in the VCC position
and the
SHDN
jumper (JU2) in the VCC position.
7) Turn on the DC supply. The supply current should
read approximately 210mA.
8) Activate the RF generator’s output. Set the RF gen-
erator’s output to produce a reading of +30dBm on
the power meter. Verify that the voltmeter reads
+3.3V. Iteratively adjust the power supply’s output
and the RF generator’s output to produce a +3.3V
reading on the voltmeter and a reading of +30dBm
on the power meter. The supply current should
increase to approximately 750mA.
Test Equipment Required
This section lists the test equipment recommended to
verify operation of the MAX2251. It is intended as a guide
only, and some substitutions are possible:
• An RF signal generator capable of delivering at least
+10dBm of output power at the operating frequency
with TDMA modulation (HP E4433G or equivalent)
• An RF power sensor capable of handling at least
+20dBm of output power at the operating frequency
(HP 8482A, or equivalent)
• A 20dB high-power attenuator
• An RF power meter capable of measuring up to
+20dBm of output power at the operating frequency
(HP EPM-441A or equivalent)
• An RF spectrum analyzer capable of measuring
ACPR in NADC modulation mode and covering the
MAX2251’s operating frequency range (Rohde and
Schwarz FSEA20, for example)
• A power supply capable of up to 1.5A at +2.8V to
+4.5V
• A high-impedance voltmeter for measuring the actual
operating voltage
• An ammeter for measuring the supply current
(optional)
• Two 50Ω SMA cables
• A network analyzer (HP 8753D, for example) to mea-
sure small-signal return loss and gain (optional)
2
_______________________________________________________________________________________
MAX2251 Evaluation Kit
Layout Issues
A good PC board is an essential part of an RF circuit
design. The EV kit PC board can serve as a guide for lay-
ing out a board using the MAX2251. Keep traces carry-
ing RF signals as short as possible to minimize radiation
and insertion loss due to the PC board. Each VCC node
on the PC board should have its own decoupling capaci-
tor. This minimizes supply coupling from one section of
the IC to another. Using a star topology for the supply
layout, in which each VCC node on the circuit has a sep-
arate connection to a central VCC node, can further mini-
mize coupling between sections of the IC.
Evaluates: MAX2251
V
CC
A2
A3
R4
11k
1%
V
CC
L2
7.15nH
C11
100pF
C12
10pF
W = 85
L = 238
RFOUT
SMA
W = 85
L = 315
OUT
B4
C14
4.7pF
W = 12
L = 125
C13
220pF
TPI
TEST POINT
C9
4700pF
A4
A1
GND
GND
GND
BIAS2
V
CC
D1
C6
100pF
D2
W = 18
L = 150
L3
R2
10k
R1
10k
V
CC
JU1
C15
V
CC
JU2
L1
4.7nH
C7
0.01µF
C3
9pF
W = 18
L = 80
RFIN
SMA
U1
MAX2251
IN
B3
OUT
SHDN D3
D4
C1
C4
C10
0.01µF
MODE
BIAS1
GND
R3
47.5k
1%
W=3
L = 76
W = 35
L = 187
C5
100pF
B1
FERRITE
C4
0.01µF
V
CC
V
CC
C1
4.7µF
GND
B2
B1
V
CC
GND
PD_OUT
GND
C3
C2
Figure 1. MAX2251 EV Kit Schematic
_______________________________________________________________________________________
3
MAX2251 Evaluation Kit
Evaluates: MAX2251
1.0"
1.0"
Figure 2. MAX2251 EV Kit—Component Placement Guide
Figure 3. MAX2251 EV Kit PC Board Layout—Component Side
1.0"
Figure 4. MAX2251 EV Kit PC Board Layout—Ground Plane
4
_______________________________________________________________________________________
MAX2251Evaluation Kit
Evaluates: MAX2251
1.0"
1.0"
Figure 5. MAX2251 EV Kit PC Board Layout—Solder Side
Figure 6. MAX2251 EV Kit PC Board Layout—Power Plane
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________
5
© 2000 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
