MAXIM MAX2745EVKIT

19-3325; Rev 0; 7/04
MAX2745 Evaluation Kit
The MAX2745 evaluation kit (EV kit) simplifies evaluation of the MAX2745 global positioning system (GPS),
radio frequency (RF), front-end IC. It enables testing of
the device’s RF performance and requires no additional
support circuitry. The EV kit’s signal inputs and outputs
use SMA connectors to facilitate the connection of RF
test equipment.
Features
♦ Easy Evaluation of the MAX2745
♦ +2.4V to +3.6V Single-Supply Operation
♦ Jumpers for Digital Control and Shutdown
♦ All Critical Peripheral Components Included
Ordering Information
Component Suppliers
SUPPLIER
PHONE
FAX
PART
TEMP RANGE
IC PACKAGE
MAX2745EVKIT
-40°C to +85°C
48 TQFP-EP*
Alpha
360-647-2360
360-671-4936
ATC
949-583-9119
949-583-9213
CoilCraft
847-639-6400
847-639-1469
Kayama
219-489-1533
219-489-2261
Murata
770-436-1300
770-436-3030
*EP = Exposed paddle.
**These components are for internal test purposes.
***These are the optional components. See the instructions on
the schematic for more details.
Note: Indicate you are using the MAX2745 when contacting
these manufacturers.
DESIGNATION
C1, C3, C6, C7,
C9–C15, C17,
C22, C33, C53,
C54,
C109–C114
C2, C23, C32
C4, C8
C5
QTY
22
DESCRIPTION
100nF ±10% (0402) capacitors
Murata GRM155R61A104K
3
100pF ±5% (0402) capacitors
Murata GRM1555C1H101J
2
220pF ±10% (0402) capacitors
Murata GRM155R71H221K
1
1000pF ±10% (0402) capacitor
Murata GRM155R71H102K
Component List
DESIGNATION
QTY
DESCRIPTION
C98
1
1.0µF ±20% (0603) capacitor
Taiyo Yuden JMK107BJ105MA-B
C101
1
10pF ±0.5pF (0402) capacitor
Murata GRM1555C1H100B
C102
1
1pF ±0.1pF (0402) capacitor
Murata GRM1555C1H1R0B
C105, C106
2
1.0µF ±10% (2012) capacitors
AVX TAJR105K016
C107
1
10nF ±10% (0402) capacitor
Murata GRM155R71C103K
F5
1
1.575GHz GPS RF saw filter
Murata SAFSE1G57AB0T00R00
J5
1
Connector DSUB 25-R
DB25 M PC board connector
AMP 747238-4
J19–J22,
J35–J38
0**
3
1500pF ±10% (0402) capacitors
Murata GRM155R71H152K
C18, C19
2
39pF ±5% (0402) capacitors
Murata GRM1555C1H390J
C27–C30,
C48–C51
0**
C36, C43, C47,
C52
4
22pF ±5% (0402) capacitors
Murata GRM1555C1H220J
J24, J26, J28,
J33, J34
5
SMA edge-mount connectors
Johnson 142-0701-801
C66
1
12pF ±5% (0402) capacitor
Murata GRM1555C1H120J
JP1–JP12
12
Shunts
Digi-Key S9000-ND
C80
0***
JP1–JP6, JP12
7
2-pin headers, 0.1in center
Sullins PTC36SAAN
C81, C100
2
JP7–JP11
5
3-pin headers, 0.1in center
Sullins PTC36SAAN
C16, C59, C60
Open (0402) capacitors
Open ±10% (0402) capacitor
Murata
6800pF ±10% (0402) capacitors
Murata GRM155R71E682K
Open, SMA edge-mount connectors
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
Evaluates: MAX2745
General Description
MAX2745 Evaluation Kit
Evaluates: MAX2745
Component List (continued)
DESIGNATION
QTY
L58
1
L60
0***
DESIGNATION
QTY
8.2nH ±0.1nH (0402) inductor
Murata LQP15MN8N2B02
S2, S3
2
DIP switches SW4 SMT
CTS 204-12ST
Open ±0.1nH (0402) inductor
Murata
TP1–TP5
5
Test points, PC mini, 0.040 red
Digi-key 5000K-ND
U1
0***
U3
1
MAX2745ECM IC, GPS RF, SM
Maxim MAX2745ECM
U4
1
MAX8510EXK27 low-noise linear
regulator
Maxim MAX8510EXK27
U12
1
Hex buffer/driver with open drain
Texas Instruments SN74LV07ADR
Y1
1
16.368327MHZ XTL
Rakon IDD30UM-1SJ
16.367MHz/XZB548
DESCRIPTION
R1
1
70kΩ ±1% (0402), 1/16W resistor
R5, R8
2
820Ω ±1% (0402), 1/16W resistors
R6, R18, R19,
R20, R27, R69,
R70, R77
8
0Ω ±1% (0402), 1/16W resistors
R9
1
100kΩ ±1% (0402), 1/16W resistor
R10–R13
4
200Ω ±1% (0402), 1/16W resistors
R14–R17
4
10kΩ ±1% (0402), 1/16W resistors
R22–R25
0**
Open, ±1%, 1/16W resistors
R59
0***
Open, ±1% (0402), 1/16W resistor
R62
1
22.1kΩ ±1% (0402), 1/16W resistor
R71
1
220Ω ±5% (0402), 1/10W resistor
R79–R86
8
30kΩ ±1% (0402), 1/16W resistors
DESCRIPTION
Open TXCO, 16.367667MHz, SM
Rakon
**These components are for internal test purposes.
***These are the optional components. See the instructions on the schematic for more details.
Detailed Description
The MAX2745 EV kit simplifies evaluation of the
MAX2745 GPS RF front-end IC. It enables testing of the
device’s RF performance and requires no additional
support circuitry. The EV kit’s signal inputs and outputs
use SMA connectors to facilitate the connection of RF
test equipment. In this section, detailed descriptions of
the EV board as well as the control interface/software
are given to facilitate better evaluation of the IC.
DC Power Supply
The MAX2745 EV kit requires three different power supplies:
• VINDC (JP3) is the main power supply for the
MAX2745 IC and the external RF circuitry such as
the TCXO. This VINDC supply powers the MAX8510
LDO, which produces 2.85V output with extremely
low noise. If different supply voltages are desired to
test the IC, bypass the LDO and directly power the
board through JP2. See the Jumper Description section for more details.
• VDD18 (JP1) is the 1.6V to 2.3V supply voltage
needed to test the voltage booster section. Do not
use VDD18 for normal operation. See the Jumper
Description section for more details.
2
• VDD5V (JP12) is the power supply for the I2C* control interface. It is not required if the control interface
is not used.
I/O Ports
The MAX2745 EV kit has one RF input port, three IF output ports, one clock output port, and one PC control port.
• RF_IN (J24) is the GPS RF signal input port with
SMA connector.
• VCMOUT_1P/VCMOUT_1N/DOUT are the IF output ports.
• CKOUT is the 16MHz/32MHz clock output port.
• J5 is the 25-pin PC parallel control port.
Digital Controls
There are two DIP switches (S2, S3) on the MAX2745
EV kit that provide eight digital controls. Refer to the
MAX2745 data sheet for more details.
*Purchase of I2C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associate Companies, conveys
a license under the Philips I2C Patent Rights to use these components in an I2C system, provided that the system conforms
to the I2C Standard Specification as defined by Philips.
_______________________________________________________________________________________
MAX2745 Evaluation Kit
1) JP9—SHDN. Connect pin 2 to pin 3 (GND) for normal operation.
2) JP7—TCXO power supply. By default the MAX2745 EV
kit uses a 16MHz crystal, so leave this jumper open.
3) JP5—External LNA supply. Refer to the MAX2745
data sheet for more details.
4) JP6—Short this jumper when testing the voltage
booster. When JP6 is shorted, JP2 MUST be open
and 1.6V to 2.3V supply is expected at JP1
(VDD18).
5) JP10—Reserved. Pin 2 MUST be shorted to pin 1
(GND) for normal operation.
6) JP8—Voltage booster enable. Short pin 2 to pin
3 (VDD) to disable the voltage booster (normal operation).
7) JP11—SHDN of the MAX8510 LDO. Connect pin
2 to pin 1 (VDD) to enable the MAX8510 (normal operation).
8) JP2—Short this jumper to connect the MAX8510 LDO
output to the power supply of the EV board. If a supply
voltage other than 2.85V is desired, leave JP2 open
and connect the new supply voltage to pin 1 of JP2.
When the voltage booster is enabled, JP2 MUST be
open and NO supply is allowed on either pin.
Control Software
The control software is needed to test the VSPORT of
the MAX2745. It is mainly for internal test purposes and
not required for normal operation. Refer to the
MAX2745 data sheet for more details.
Quick Start
• Two power supplies capable of up to 1A at +1.6V to
+6.0V
• One ammeter for measuring the supply current
(optional)
• 50Ω SMA cables
• A network analyzer (HP 8753D, for example) to measure small-signal return loss and gain (optional)
• An oscilloscope to check the digital IF output
Connections and Setup
This section provides a step-by-step guide to operating
the EV kit and testing the device’s function. Do not turn
on the DC power or RF signal generators until all
connections are made:
1) Connect a DC supply set to +3.3V to the VDC and
GND terminals on the EV kit. Do not turn on the supply.
2) Connect a DC supply set to +5.0V to the 5VDC on
the EV kit. Do not turn on the supply.
3) Connect one RF signal generator to the RFIN SMA
connector; do not turn on the generator’s output.
Set the output frequency to 1575.420000MHz. Set
the power level to -120dBm.
4) Connect the ACOMOUT+/- output on the EV kit to a
spectrum analyzer through an SMA cable.
5) Connect the EV kit to a PC through a parallel cable.
6) Run the control software on an IBM-compatible PC.
7) Set the digital controls to the appropriate states
(refer to the MAX2745 data sheet for the digital control settings).
8) Turn on the DC supplies. The supply current should
read approximately 20mA.
9) Activate the RF generator’s output.
10) Check the IF outputs.
The MAX2745 EV kit is fully assembled and factory tested. Follow the instructions in the Connections and
Setup section for proper device evaluation.
11) Check other features of the MAX2745, e.g., 16MHz
clock output, voltage booster, temperature-sensor
output, etc.
Test Equipment Required
Layout Issues
This section lists the recommended test equipment to
verify operation of the MAX2745. It is intended as a
guide only, and some substitutions are possible.
• An RF signal generator capable of delivering RF
power as low as -120dBm and as high as 0dBm at
the 1575.42MHz operating frequency (HP E4433B,
or equivalent)
• An RF spectrum analyzer that covers the MAX2745
operating frequency range, as well as a few harmonics (FSEB20, for example)
A good PC board is an essential part of RF circuit
design. The EV kit PC board can serve as a guide for
laying out a board using the MAX2745. Keep traces
carrying RF signals as short as possible to minimize
radiation and insertion loss. Use impedance control on
all RF signal traces. The VCC node on the PC board
should have decoupling capacitors to the closest
ground. Refer to the Layout section of the MAX2745
data sheet for more information.
_______________________________________________________________________________________
3
Evaluates: MAX2745
Jumper Description
There are eight jumpers on the MAX2745 EV kit besides
the power-supply jumpers.
TI_QP
TI_QN
TI_IN
TI_IP
!
!#
!
!
"
##
*
#'###$) !
'$)
-(. +,
+,
!
VRF IN
$ "
"
#
PSAVE
XTAL_LFS
XTAL_SEL
BST_CTRL_AH
IEXT_LNA
'$
!
$ "
"
"
#
1
#'#$2
"
'$
#
#
$
"
"
POPULATE L60, C80
TO USE 32.736 MHz CRYSTAL,
"
#
"
$ # !
"
#
$ !
$ !
#
'
# # & !
' (
"
#
$
CKOUT
#
!#
DOUT1
#"
!
#
$
$ $
$
VCO_CTRL
TEMPOUT
#
"
#
"
TO USE 16.368 MHz CRYSTAL, DNP L60, C80
TO USE TCXO, DNP Y1, POPULATE U1
#
"
$
$
#
"
!
VCMOUT_1N
"
"
!"
!
!
!
TO_IP
TO_IN
TO_QP
TO_QN
!
VCMOUT_1P
GMCTRL_BPF
ODS
CFS
COE
# 1
1
1
#
$ #
' (
!
"
1 1 # #1 $ !
!
!
' (
#
" " # # "
#
#
$ !
$ $ !
$ !
$/
#
TO USE CRYSTAL, DNP U1, POPULATE Y1
#
4
#
0
"
Evaluates: MAX2745
MAX2745 Evaluation Kit
Figure 1. MAX2745 EV Kit Schematic
_______________________________________________________________________________________
MAX2745 Evaluation Kit
Evaluates: MAX2745
1.0"
1.0"
Figure 2. MAX2745 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX2745 EV Kit PC Board Layout—Layer 2
1.0"
1.0"
Figure 4. MAX2745 EV Kit PC Board Layout—Layer 3
Figure 5. MAX2745 EV Kit PC Board Layout—Component Side
_______________________________________________________________________________________
5
Evaluates: MAX2745
MAX2745 Evaluation Kit
1.0"
Figure 6. MAX2745 EV Kit PC Board Layout—Secondary 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.
6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.