MAXIM MAX2027EVKIT

19-2686; Rev 0; 11/02
MAX2027 Evaluation Kit
Features
♦ Fully Assembled and Tested
This EV kit provides a list of equipment required to evaluate the device, a straightforward test procedure to verify functionality, a circuit schematic, a bill of materials
(BOM), and artwork for each layer of the PC board.
Contact MaximDirect sales at 888-629-4642 to check
pricing and availability of these kits.
♦ Noise Figure: 4.7dB at Maximum Gain
♦ 50MHz to 400MHz Frequency Range
♦ Variable Gain: -8dB to +15dB
♦ Output IP3: 40dBm (All Gain Settings at 50MHz)
♦ Digitally Controlled Gain with 1dB Resolution and
±0.2dB Accuracy
Ordering Information
Component Suppliers
SUPPLIER
PHONE
PART
WEBSITE
Coilcraft
847-639-6400
www.coilcraft.com
Johnson
507-833-8822
www.johnsoncomponents.com
Murata
770-436-1300
www.murata.com
MAX2027EVKIT
TEMP RANGE
IC PACKAGE
-40°C to +85°C
20 TSSOP-EP*
*EP = Exposed paddle.
Component List (Unmatched)
DESIGNATION
QTY
DESCRIPTION
C1, C3, C4, C6, C7, C10 (Note 1)
6
1000pF ±5%, 50V COG ceramic capacitors (0603)
Murata GRM1885C1H102J
C2, C5
2
100pF ±5%, 50V COG ceramic capacitors (0603)
Murata GRM1885C1H101J
C8, C9
0
Not installed
J1, J2
2
PC board edge-mount SMA RF connectors (flat-tab launch)
Johnson 142-0741-856
J3
1
Header 5 × 2 (0.100 spacing for 0.062in thick board)
Molex 10-88-1101 or equivalent
J4
0
Not installed
L1
1
330nH ±5% wire-wound IND (0805)
Coilcraft 0805CS-331XJBC
L2
1
680nH ±5% wire-wound IND (1008)
Coilcraft 1008CS-681XJBC
L3
1
0Ω resistor (0603) (used as a jumper for unmatched board)
L4
0
Not installed
R1
1
825Ω ±1% resistor (0603)
R2–R6
5
47kΩ ±5% resistors (0603)
U1
1
MAX2027EUP-T
Note 1: If matching is not required, C3 is installed using one pad of L4 and one pad of C3.
________________________________________________________________ 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: MAX2027
General Description
The MAX2027 evaluation kit (EV kit) simplifies the evaluation of the MAX2027 high-linearity, digitally controlled,
variable-gain amplifier. The kit is fully assembled and
tested at the factory. Standard 50Ω SMA connectors
are included for the input and output to allow quick and
easy evaluation on the test bench.
Evaluates: MAX2027
MAX2027 Evaluation Kit
Table 1. Suggested Components for
Matching
FREQUENCY
(MHz)
COMPONENT
VALUE
SIZE
Table 2. Attenuation Setting vs. GainControl Bits
ATTENUATION
(dB)
B4
(16dB)
B3*
(8dB)
B2
(4dB)
B1
(2dB)
B0
(1dB)
L3, L4
18nH
0603
C8, C9
8pF
0603
0
0
0
0
0
0
L3, L4
15nH
0603
1
0
0
0
0
1
C8, C9
8pF
0603
2
0
0
0
1
0
L3, L4
11nH
0603
3
0
0
0
1
1
C8, C9
7pF
0603
4
0
0
1
0
0
L3, L4
10nH
0603
5
0
0
1
0
1
C8, C9
5pF
0603
6
0
0
1
1
0
7
0
0
1
1
1
Quick Start
8
0
1
0
0
0
The MAX2027 EV kit is fully assembled and factory tested. Follow the instructions in the Connections and
Setup section for proper device evaluation. Table 2 lists
the attenuation setting vs. gain-control bits.
9
0
1
0
0
1
10
0
1
0
1
0
11
0
1
0
1
1
12
0
1
1
0
0
Test Equipment Required
13
0
1
1
0
1
• DC supply capable of delivering 5.25V and 100mA of
continuous current
14
0
1
1
1
0
15
0
1
1
1
1
16
1
X
0
0
0
17
1
X
0
0
1
18
1
X
0
1
0
19
1
X
0
1
1
20
1
X
1
0
0
21
1
X
1
0
1
22
1
X
1
1
0
23
1
X
1
1
1
200
250
300
400
• HP 8648 (or equivalent) signal source
• HP 8561E (or equivalent) spectrum analyzer capable
of covering the MAX2027’s frequency range as well
as a few harmonics
• Two digital multimeters (DMMs) to monitor VCC and
ICC, if desired
• HP8753D (or equivalent) network analyzer to measure
return loss and gain
• Lowpass filters to attenuate harmonic output of signal
sources, if harmonic measurements are desired
*Enabling B4 disables B3.
Connections and Setup
This section provides a step-by-step guide to testing
the basic functionality of the EV kit. As a general precaution to prevent damaging the outputs by driving
high-VSWR loads, do not turn on DC power or RF
signal generators until all connections are made.
Gain Setting
Connect the header pins for B4–B0 to GND for maximum gain (15dB, typ). See Table 2 for other gain setting configurations. To set a logic high on B4–B0, leave
the respective header pin unconnected as on-board
resistors pull up the logic to +5V. To control B4–B0
using external logic (voltage limits per data sheet),
2
ensure that +5V is applied to the chip. Failure to do so
can cause the on-chip ESD diodes to draw significant
current and may damage the part.
Testing the Supply Current
1) Connect 50Ω terminations to RF_IN and RF_OUT.
2) With the DC supply disabled, set it to +5.0V (through
a low internal resistance ammeter, if desired) and
connect to the +5V and GND terminals on the EV kit.
If available, set the current limit to 100mA.
3) Enable the DC supply; the supply current should
read approximately 60mA.
_______________________________________________________________________________________
MAX2027 Evaluation Kit
2) Connect the spectrum analyzer to the RF_OUT SMA
connector. Set the spectrum analyzer to a center
frequency of 50MHz and a total span of 1MHz.
3) With the DC supply disabled, set it to +5.0V (through
a low internal-resistance ammeter if desired) and
connect to the +5V and GND terminals on the EV kit.
If available, set the current limit to 100mA.
4) Connect B4–B0 to GND for 0dB attenuation.
5) Enable the DC supply, and then activate the RF generator’s output. A 50MHz signal shown on the spectrum
analyzer display should indicate a magnitude of
approximately 5dBm. Be sure to account for external
cable losses.
6) (Optional) Gain can be determined with a network
analyzer. This has the advantage of displaying gain
over a swept frequency band, in addition to displaying input and output return loss. Refer to the network
analyzer manufacturer’s user manual for setup
details.
Detailed Description
Figure 1 is the schematic for the EV kit as shipped. This
circuit is internally matched for operation up to 150MHz.
Component pads for external matching components, L3,
L4, C8, and C9, are included to allow modification for
higher frequency operation (see Table 1 for suggested
components for additional frequencies). C1, C3, and C4
are DC-blocking capacitors for the RF_IN, ATTNOUT, and
RF_OUT ports. To reduce the possibility of noise pickup,
C2, C5, C6, and C7 form the VCC decoupling network.
Note the location of each component.
Modifying the MAX2027 EV Kit
The EV kit can be configured for use at any frequency
between 50MHz and 400MHz. See Table 1 for the correct matching component values for the desired operating frequency.
Layout Considerations
The MAX2027 evaluation board can be a guide for your
board layout. Pay close attention to thermal design and
close placement of parts to the IC. The MAX2027 package exposed paddle (EP) conducts heat from the part
and provides a low-impedance electrical connection.
The EP must be attached to the PC board ground
plane with a low thermal and electrical impedance contact. Ideally, this can be achieved by soldering the
backside package contact directly to a top metal
ground plane on the PC board. Alternatively, the EP
can be connected to a ground plane using an array of
plated vias directly below the EP.
Depending on the RF ground-plane spacing, large surface-mount pads in the RF path may need the ground
plane relieved under them to reduce shunt capacitance.
_______________________________________________________________________________________
3
Evaluates: MAX2027
Testing the Power Gain
1) Connect the RF signal generator to the RF_IN SMA
connector. Do not turn on the generator’s output. Set
the generator to an output frequency of 50MHz, and
set the generator power level to -10dBm.
Evaluates: MAX2027
MAX2027 Evaluation Kit
+5V
C7
RF_IN
1
GND
20
2
GND
19
3
ATTNOUT
18
RF_TEST*
J4
C2
C1
L3
J1
C9*
L4*
C8*
4
GND
GND
17
5
GND
GND
16
6
B4
AMPIN
15
+5V
C3
R6
R5
R4
R3
R2
B4
L1
7
B3
AMP
BIAS
IBIAS
14
B3
C10
8
B2
9
B1
ISET
ATTENUATION
LOGIC CONTROL
R1
13
B2
C4
12
RF_OUT
J2
B1
L2
10
B0
11
B0
C5
B3
*THESE COMPONENTS ARE LEFT UNINSTALLED FROM THE FACTORY.
SEE TABLE 2 FOR SUGGESTED MATCHING COMPONENTS AT
DIFFERENT OPERATION FREQUENCIES. RF_TEST ALLOWS FOR
INTERSTAGE MEASUREMENTS.
J3-9
B1
J3-7
GND
J3-5
J3-3
J3-1
J3
J3-10
J3-8
B4
J3-6
B2
J3-4
B0
GND
J3-2
+5V
TOP VIEW OF HEADER
Figure 1. MAX2027 EV Kit Schematic
4
+5V
_______________________________________________________________________________________
C6
MAX2027 Evaluation Kit
Evaluates: MAX2027
POWER SUPPLY
3-OUT, HPIB
(AG E3631A)
BENCH
MULTIMETER HPIB
(HP 34401A)
+5V
GND
RF SIGNAL GENERATOR
(HP 8648D)
B4
U1
B3
MAX2027
B2
CONTROL
INPUTS
B1
RF_IN
RF_OUT
B0
RF SPECTRUM ANALYZER
(HP 856xE)
Figure 2. Test Setup Diagram
_______________________________________________________________________________________
5
Evaluates: MAX2027
MAX2027 Evaluation Kit
MULTIPLE VIAS CONNECT EXPOSED
PADDLE TO LAYER 2 GROUND PLANE
FOR THE GENERIC BOARD, C3 IS INSTALLED USING
ONE PAD OF L4 AND ONE PAD OF C3 AS SHOWN.
Figure 3. MAX2027 EV Kit Component Placement Guide—Component Side
6
_______________________________________________________________________________________
MAX2027 Evaluation Kit
Evaluates: MAX2027
Figure 4. MAX2027 EV Kit Component Placement Guide—Top
Silkscreen
Figure 5. MAX2027 EV Kit Component Placement Guide—
Bottom Silkscreen
Figure 6. MAX2027 EV Kit PC Board Layout—Primary
Component Side
Figure 7. MAX2027 EV Kit PC Board Layout—GND Layer
(Layer 2)
_______________________________________________________________________________________
7
Evaluates: MAX2027
MAX2027 Evaluation Kit
Figure 8. MAX2027 EV Kit PC Board Layout—Route Layer
(Layer 3)
Figure 9. MAX2027 EV Kit PC Board Layout—Secondary Side
Figure 10. MAX2027 EV Kit PC Board Layout—Top Soldermask
Figure 11. MAX2027 EV Kit PC Board Layout—Bottom
Soldermask
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.
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© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.