19-1620; Rev 0; 1/00
MAX2683/MAX2684 Evaluation Kits
General Description
The MAX2683/MAX2684 evaluation kits (EV kits) simplify
evaluation of the MAX2683/MAX2684 3.4GHz to 3.8GHz
downconverter mixers. The EV kits are fully assembled
and tested, allowing simple evaluation of all device func-
tions. All signal ports utilize SMA connectors, providing a
convenient interface to RF test equipment.
The MAX2683/MAX2684 are downconversion mixers
intended for operation in the 3.4GHz to 3.8GHz frequen-
cy range. The MAX2683 is optimized for downconversion
to IF frequencies between 100MHz and 400MHz, and
allows high-side or low-side LO injection. The MAX2684
is optimized for IF frequencies between 800MHz to
1000MHz and only allows low-side LO injection. A logic-
level enabled LO frequency doubler allows the external
LO source to run at half frequency, or at full frequency if
disabled. As assembled, the MAX2683/MAX2684 EV kits
are configured for operation of the LO at half frequency.
A few simple component changes configure the EV kit
for operation of the LO at full frequency. In addition, an
external resistor allows adjustment of device linearity and
supply current.
Features
o
Easy Evaluation of MAX2683/MAX2684
o
All Critical Peripheral Components Included
o
SMA Input and Output Signal Connectors
o
RF Input Matched to 50Ω at 3600MHz
o
IF Output Matched to 50Ω at 300MHz (MAX2683)
o
IF Output Matched to 50Ω at 900MHz (MAX2684)
o
Fully Assembled and Tested
Evaluate: MAX2683/MAX2684
Ordering Information
PART
MAX2683EVKIT
MAX2684EVKIT
*Exposed paddle
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
IC PACKAGE
16 TSSOP-EP*
16 TSSOP-EP*
MAX2683 Component List
DESIGNATION QTY
C1
1
DESCRIPTION
3300pF ±10% ceramic capacitor (0402)
Murata GRM36X7R332K050 or
Taiyo Yuden UMK105B332KW
1pF ±0.1pF ceramic capacitor (0603)
Murata GRM39COG010B050
100pF ±5% ceramic capacitors (0603)
Murata GRM39COG101J050 or
Taiyo Yuden UMK107CH101JZ
10µF, 10V tantalum capacitor
AVX TAJB106M010
Not installed
1000pF ±10% ceramic capacitor
(0603) Murata GRM39X7R102K050
8.2pF ±0.25pF ceramic caps (0603)
Murata GRM39COG8R2C050 or
Taiyo Yuden UMK107CH8R2CZ
3.3pF ±0.1pF ceramic cap (0603)
Murata GRM39COG3R3B050
3-pin header
1.2nH ±0.2nH inductor (0402)
Murata LQP10A1N2C00
T1
U1
VCC, GND
None
None
None
None
1
1
2
1
1
1
1
DESIGNATION QTY
L3, L4
L5
R1, R2
R3
R4
RFIN, LOX, IF
2
1
2
1
0
3
DESCRIPTION
39nH ±5% inductors (0603)
Murata LQG11A39NJ00
3.9nH ±3nH inductor (0603)
Murata LQG11A3N9S00
1.21kΩ ±1% resistors (0603)
1.50kΩ ±1% resistor (0603)
Not installed
SMA connectors (PC edge mount)
EFJohnson 142-0701-801
Balun transformer, B4F type
Toko 617DB-1018
MAX2683EUE (16-pin TSSOP)
Test points
Shunt (JU1)
MAX2683/MAX2684 PC board
MAX2683/MAX2684 data sheet
MAX2683/MAX2684 EV kit data sheet
C2
1
C3, C6, C12
3
C4
C5
C7
1
0
1
C8, C9
2
C10
JU1
L1
1
1
1
________________________________________________________________
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.
MAX2683/MAX2684 Evaluation Kits
Evaluate: MAX2683/MAX2684
MAX2684 Component List
DESIGNATION QTY
C1
1
DESCRIPTION
3300pF ±10% ceramic cap (0402)
Murata GRM36X7R332K050 or
Taiyo Yuden UMK105B332KW
1pF ±0.1pF ceramic capacitor (0603)
Murata GRM39COG010B050
100 pF ±5% ceramic capacitors (0603)
Murata GRM39COG101J050 or
Taiyo Yuden UMK107CH101JZ
10µF, 10V tantalum capacitor
AVX TAJB106M010
Not installed
1000pF ±10% ceramic cap (0603)
Murata GRM39X7R102K050
8.2pF ±0.25pF ceramic caps (0603)
Murata GRM39COG8R2C050 or
Taiyo Yuden UMK107CH8R2CZ
Not installed
None
JU1
L1
1
1
3-pin header
None
1.2nH ±0.2nH inductor (0402)
Murata LQP10A1N2C00
None
1
1
MAX2683/MAX2684 data sheet
MAX2683/MAX2684 EV kit data sheet
1
MAX2683/MAX2684 PC board
T1
U1
VCC, GND
None
1
1
2
1
Balun transformer, B4F type
Toko 617DB-1018
MAX2684EUE (16-pin TSSOP)
Test points
Shunt (JU1)
DESIGNATION QTY
L3, L4
L5
R1, R2
R3
R4
RFIN, LOX, IF
2
1
2
1
0
3
DESCRIPTION
6.8nH ±5% inductors (0603)
Murata LQG11A6N8J00
3.9nH ±0.3nH inductor (0603)
Murata LQG11A3N9S00
1.21kΩ ±1% resistors (0603)
301Ω ±1% resistor (0603)
Not installed
SMA connectors (PC edge mount)
EFJohnson 142-0701-801
C2
1
C3, C6, C12
3
C4
C5
C7
1
0
1
C8, C9
C10
2
0
Component Suppliers
SUPPLIER
AVX
EFJohnson
Murata
Taiyo
Yuden
Toko
PHONE
FAX
WEB
www.
avxcorp.com
www.
efjohnson.com
www.
murata.com
www.
T-Yuden.com
www.
tokoam.com
843-448-9411 843-448-1943
402-474-4800 402-474-4858
800-831-9172 814-238-0490
800-348-2496 847-925-0899
800-PIK-TOKO 708-699-1194
•
Two low-noise RF-signal generators or equivalent
(50Ω) sine-wave sources capable of delivering at
least 0dBm of output power up to 4GHz. One gen-
erator is required for the RF signal source, while the
second generator is required for the LO signal
source.
One HP 8561E RF-spectrum analyzer or equivalent
that covers the downconverter mixer’s output fre-
quency range, as well as a few harmonics (6GHz).
Three 50Ω SMA cables (RG-58A/U or equivalent).
Optional: digital multimeters (DMMs) to monitor DC
supply voltage and supply current.
•
•
•
Connections and Setup
This section provides step-by-step instructions for get-
ting the EV kit up and running:
1)
DC Power Supply:
Set the power-supply voltage to
+5V. Turn the power supply off and connect 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 voltmeter in parallel
with the VCC and GND connections to measure the
supply voltage delivered to the device.
Test Equipment Required
This section lists the test equipment required for evalu-
ating the MAX2683/MAX2684:
•
One power supply capable of providing 100mA of
supply current over the supply voltage range of
+2.7V to +5.5V.
2
_______________________________________________________________________________________
MAX2683/MAX2684 Evaluation Kits
2)
RF Signal Source:
Set one signal generator to an
RF frequency of 3.6GHz at an output power level of
-20dBm. Turn the output of the signal generator off.
Connect the signal generator to the RF port SMA
connector using a 50Ω SMA cable.
3)
LO Signal Source:
The MAX2683/MAX2684 can be
configured for full- or half-frequency operation of
the external LO signal source. As assembled, the
MAX2683/MAX2684 EV kits are configured for half-
frequency operation of the LO signal source. The
half-frequency LO port, LOX2, is coupled to the
MAX2683/MAX2684 EV kit LO port SMA connector,
while the LOX1 port is left unconnected.
To evaluate the devices with the LO doubler
enabled, be sure jumper JU1 is shorted to GND
(ENX2 = GND). Set the LO signal generator output
power to -5dBm at a frequency of 1650MHz
(MAX2683) or 1350MHz (MAX2684). Turn the out-
put of the signal generator off. Connect the signal
generator to the LO port SMA connector using a
50Ω SMA cable.
Evaluation of the devices with full-frequency opera-
tion of the LO signal source requires two compo-
nent changes. Remove inductor L5 and leave the
LOX2 port unconnected. Short the unpopulated
pads of resistor R4 with a 0Ω resistor. Disable the
LO frequency doubler by shunting jumper JU1 to
VCC (ENX2 = VCC). Set the LO signal generator
output power to -5dBm, at a frequency of 3300MHz
(MAX2683) or 2700MHz (MAX2684). Turn the out-
put of the signal generator off. Connect the signal
generator to the LO port SMA connector using a
50Ω SMA cable.
4)
Spectrum Analyzer:
Connect the spectrum analyz-
er to the IF port SMA connector using a 50Ω SMA
cable. Set the center frequency of the spectrum
analyzer to 300MHz (MAX2683) or 900MHz
(MAX2684). Set the reference level of the spectrum
analyzer to -10dBm and the span to 1MHz.
300MHz for the MAX2683 EV kit and 0.8dB at 900MHz
for the MAX2684 EV kit.
Evaluate: MAX2683/MAX2684
Detailed Description
This section describes the circuitry surrounding the
MAX2683/MAX2684 EV kits.
Figure 1 is the schematic
for the MAX2683/MAX2684 EV kits as assembled. For
more detailed information covering device operation,
refer to the MAX2683/MAX2684 data sheet.
RF Input
The RFIN port of the MAX2683/MAX2684 is internally
biased and requires a DC-blocking capacitor, as well as
a matching network for optimum power transfer.
Capacitor C1 functions as a DC block, while inductor L1
and capacitor C2 function as a matching network, tuning
the RF input of the device for maximum gain at 3.6GHz.
LO Input and LO Frequency
Doubler Control
The MAX2683/MAX2684 include a logic-level-enabled
LO frequency doubler. Jumper JU1 controls the LO
doubler. A logic-level low on the
ENX2
pin enables the
frequency doubler, and the external LO signal source
operates at half frequency. A logic-level high on the
ENX2
pin disables the frequency doubler, and the
external LO signal source operates at full frequency.
Half-frequency LO signals are applied to the LOX2
port, while full-frequency LO signals are applied to the
LOX1 port. Both ports are internally biased and require
a DC-blocking capacitor. The unused LO port should
be left unconnected.
The MAX2683/MAX2684 EV kits, as assembled, are con-
figured for operation of the LO signal source at half fre-
quency. Capacitor C6 functions as a DC block, while
inductor L5 improves the return loss of the port. The LOX1
port is left unconnected for half-frequency operation.
To evaluate the device with full-frequency operation of
the LO source, remove inductor L5 and leave the LOX2
port unconnected (Figure 2). Short resistor R4 with a
0Ω resistor. Capacitor C6 now functions as the DC
block for the LOX1 port.
Analysis
Turn on the power supply and RF and LO signal gener-
ators. The ammeter should read approximately 55mA
with the LO doubler enabled (ENX2 = GND) or 40mA
with the LO doubler disabled (ENX2 = V
CC
). If evaluat-
ing the MAX2683, the spectrum analyzer should show
an output power of approximately -14dBm at a center
frequency of 300MHz. If evaluating the MAX2684, the
output power should read approximately -20dBm at a
center frequency of 900MHz. Be sure to take into
account cable, board, and balun losses when calculat-
ing power gain. Typical balun losses are 0.3dB at
IF Output
The MAX2683/MAX2684 incorporate differential, open-
collector IF output ports for use in either differential or
single-ended applications. To ease evaluation of the
devices, the MAX2683/MAX2684 EV kits utilize a balun
to convert the differential signal to a single-ended sig-
nal compatible with 50Ω test equipment. The IF output
of the MAX2683 is tuned for an IF frequency of
300MHz, while the IF output of the MAX2684 is tuned
for an IF frequency of 900MHz. Inductors L3 and L4
provide DC biasing and impedance matching of the
3
_______________________________________________________________________________________
MAX2683/MAX2684 Evaluation Kits
Evaluate: MAX2683/MAX2684
VCC
1
VCC
C4
10µF
10V
C3
100pF
V
CC
BIAS
16
R1
1.21k
2
3
GND
GND
GND
U1
MAX2683
MAX2684
GND
15
C8
8.2pF
SMA
RFIN
C1
3300pF
C2
1pF
L1
1.2nH
4
5
RFIN
GND
IFOUT+
GND
14
13
L3*
39nH
R3*
1.50k
L4*
39nH
T1
BALUN TOKOB4F
SMA
IF
4
VCC
C10*
3.3pF
3
2
1
C7
1000pF
LOX1
LO MODE
LOX2
JU1
R2
1.21k
C12
100pF
GND
6
ENX2
12
6
L5
3.9nH
7
IFOUT-
LOX2
GND
11
C9
8.2pF
C6
SMA
LOX 100pF
R4
OPEN
10
9
8
LOX1
GND
C5
OPEN
* VALUES ARE FOR MAX2683 EV KIT ONLY.
REFER TO COMPONENT LIST FOR
MAX2684 VALUES.
Figure 1. MAX2683/MAX2684 EV Kits Schematic
Linearity and Supply Current Adjustment
The MAX2683/MAX2684 allow the linearity and supply
current of the device to be adjusted via an external
resistor, R1, to ground. Increased linearity also results
in increased supply current. The MAX2683/MAX2684
EV kits are assembled with a nominal R1 value of
1.21kΩ. Replace R1 with a resistor value in the range of
820Ω to 2kΩ to experiment with the linearity of the
device.
L5
OPEN
7
LOX2
C6
100pF
LO
INPUT
R4
SHORT
MAX2683
MAX2684
8
LOX1
Layout and Bypassing
Good PC board layout is an essential aspect of RF cir-
cuit design. The EV kits’ PC board can serve as a guide
for laying out a board using the MAX2683/MAX2684.
Keep PC board trace lengths as short as possible to
minimize parasitics and losses. Keep bypass capaci-
tors as close to the device as possible with low-induc-
tance connections to the ground plane.
Capacitor C4, placed near the VCC connection, and
capacitors C3 and C7, placed near the device, help to
reduce any high-frequency crosstalk. Capacitor C12
and resistor R2, placed near the
ENX2
pin on the
device, help to filter out any noise that may be coupled
into the
ENX2
pin.
Figure 2. MAX2683/MAX2684 Full-Frequency LO Port
Configuration
IFOUT+, and IFOUT- ports. Resistor R3 resistively ter-
minates the IF output. Capacitors C8 and C9 provide
impedance matching in addition to DC blocking. In the
MAX2683, C10 is also part of an impedance-matching
network. The balun provides differential to single-ended
conversion as well as 4:1 impedance transformation.
The IF output is then connected to the IF port SMA con-
nector.
4
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MAX2683/MAX2684 Evaluation Kits
Evaluate: MAX2683/MAX2684
1.0"
Figure 3. MAX2683/MAX2684 EV Kits PC Board Layout—
Component Placement Guide
1.0"
Figure 4. MAX2683/MAX2684 EV Kits PC Board Layout—
Component Side
1.0"
Figure 5. MAX2683/MAX2684 EV Kits PC Board Layout—
Ground Planes 1 and 2
1.0"
Figure 6. MAX2683/MAX2684 EV Kits PC Board Layout—
Solder Side
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