Page 1
General Description
The MAX2027 high-performance, digitally controlled
variable-gain amplifier is designed for use from 50MHz
to 400MHz.
The device integrates a digitally controlled attenuator
and a high-linearity IF amplifier in one package.
Targeted for IF signal chains to adjust gain either
dynamically or as a one-time channel gain setting, the
MAX2027 is ideal for applications requiring high performance. The attenuator provides 23dB of attenuation
range with ±0.05dB state-to-state accuracy.
The MAX2027 is available in a thermally enhanced 20pin TSSOP-EP package and operates over the -40°C to
+85°C temperature range.
Applications
Cellular Base Stations
Receiver Gain Control
Transmitter Gain Control
Broadband Systems
Automatic Test Equipment
Terrestrial Links
Features
♦ 50MHz to 400MHz Frequency Range
♦ Variable Gain: -8dB to +15dB
♦ Output IP3: 35dBm (at All Gain Settings)
♦ Noise Figure: 4.7dB at Maximum Gain
♦ Digitally Controlled Gain with 1dB Resolution and
±0.05dB State-to-State Accuracy
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
________________________________________________________________ Maxim Integrated Products 1
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
12
11
9
10
MAX2027
ATTENUATION
LOGIC
CONTROL
AMP
BIAS
GND
GND
ATTN
OUT
GND
GND
RF_IN
V
CC
V
CC
GND
AMP
IN
I
BIAS
I
SET
B2
B3
B4
GND
RF_OUT
V
CC
B0
B1
Pin Configuration/
Functional Diagram
Ordering Information
19-2601; Rev 1; 2/04
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.
PART TEMP RANGE PIN-PACKAGE
MAX2027EUP-T -40°C to +85°C 20 TSSOP-EP*
*EP = exposed pad.
Page 2
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
All Pins Input Voltage (except AMPIN, I
BIAS
, and I
SET
)
to GND................................................................-0.3V to +5.5V
Input Voltage Levels (B0–B4).....................-0.3V to (V
CC
+ 0.5V)
Input Voltage Levels (AMP
IN
and I
BIAS
)................-0.3V to +1.5V
Input Voltage Levels (I
SET
)....................................-0.3V to +1.0V
RF Input Signal .................................................................20dBm
RF Output Signal...............................................................22dBm
Continuous Power Dissipation (T
A
= +70°C)
20-Pin TSSOP-EP
(derate 21.7mW/°C above +70°C)..................................1.7W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +165°C
Lead Temperature (soldering, 10s) .................................+300°C
DC ELECTRICAL CHARACTERISTICS
(Typical application circuit, VCC= +4.75V to +5.25V, GND = 0V. No RF signals applied, and RF input and output ports are terminated
with 50Ω. R
1
= 825Ω, TA= -40°C to +85°C. Typical values are at VCC= +5V and TA= +25°C, unless otherwise noted.) (Notes 1, 2)
PARAMETER
CONDITIONS
UNITS
SUPPLY
Supply Voltage V
CC
V
Supply Current I
CC
60 75 mA
I
SET
Current I
SET
0.9 mA
CONTROL INPUTS/OUTPUTS
Control Bits Parallel 5 Bits
Input Logic High (Note 3) 2 V
Input Logic Low 0.6 V
Input Leakage Current
µA
SYMBOL
MIN TYP MAX
4.75 5.00 5.25
-1.2 +1.2
Page 3
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
_______________________________________________________________________________________ 3
AC ELECTRICAL CHARACTERISTICS
(Typical application circuit without matching, VCC= +4.75V to +5.25V, GND = 0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), R1=
825Ω, P
OUT
= 5dBm, fIN= 50MHz, 50Ω RF system impedance. Typical values are at VCC= +5V and TA= +25°C, unless otherwise
noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Frequency Range f
R
50
MHz
Gain G No attenuation
dB
Noise Figure NF Max gain 4.7 dB
Minimum Reverse Isolation Max gain 22 dB
Output 1dB Compression Point P
1dB
Max gain
dBm
OIP2
42
dBm
OIP3 All gain conditions, 5dBm/tone
dBm
2nd Harmonic 2f
IN
-44 dBc
3rd Harmonic 3f
IN
-68 dBc
RF Gain-Control Range 23 dB
Gain-Control Resolution 1dB
Attenuation Absolute Accuracy
Compared to the ideal expected
attenuation
dB
Attenuation Relative Accuracy Between adjacent states
dB
Gain Drift Over Temperature TA = -40°C to +85°C
dB
Peak-to-peak for all settings,
F
CENTER
= 75MHz
0.1
Gain Flatness Over 50MHz BW
Peak-to-peak for all settings,
F
CENTER
= 200MHz
0.2
dB
Attenuator Switching Time 50% control to 90% RF 40 ns
Input Return Loss
15 dB
Output Return Loss
15 dB
Note 1: Guaranteed by design and characterization.
Note 2: All limits reflect losses of external components. Output measurements are taken at RF OUT using the typical application
circuit.
15.5
20.6
2nd-Order Output Intercept Point
3rd-Order Output Intercept Point
f1 + f2, f1 = 50MHz, f2 = 51MHz, 5dBm/tone
34.7
0.15/
-0.05
±0.05
±0.1
400
fR = 50MHz to 250MHz, all gain conditions
fR = 50MHz to 250MHz, all gain conditions
Page 4
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
4 _______________________________________________________________________________________
Typical Operating Characteristics
(Typical application circuit, VCC= 5.0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), P
OUT
= 5dBm, R1= 825Ω, TA= +25°C, unless
otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
MAX2027 toc01
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
8065-25 -10 5 3520 50
54
56
58
60
62
64
66
68
52
-40
V
CC
= 5.25V
V
CC
= 5.0V
V
CC
= 4.75V
INPUT RETURN LOSS
vs. RF FREQUENCY (ALL STATES)
MAX2027 toc02
FREQUENCY (MHz)
INPUT RETURN LOSS (dB)
350300250200150100
30
25
20
15
10
5
0
35
50 400
OUTPUT RETURN LOSS
vs. RF FREQUENCY (ALL STATES)
MAX2027 toc03
FREQUENCY (MHz)
OUTPUT RETURN LOSS (dB)
350300250200150100
30
25
20
15
10
5
0
35
50 400
GAIN vs. RF FREQUENCY
(ALL STATES)
MAX2027 toc04
FREQUENCY (MHz)
GAIN (dB)
350300250200150100
-10
-5
0
5
10
15
20
-15
50 400
REVERSE ISOLATION vs. FREQUENCY
MAX2027 toc05
FREQUENCY (MHz)
REVERSE ISOLATION (dB)
350300250200150100
10
15
20
25
30
35
5
50 400
GAIN vs. FREQUENCY
MAX2027 toc06
FREQUENCY (MHz)
GAIN (dB)
350300100 150 200 250
11
12
13
14
15
16
17
18
10
50 400
TA = -40°C
TA = +25°C
TA = +85°C
GAIN vs. FREQUENCY
MAX2027 toc07
FREQUENCY (MHz)
GAIN (dB)
350300100 150 200 250
11
12
13
14
15
16
17
18
10
50 400
VCC = 4.75V, 5.0V, AND 5.25V
Page 5
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
_______________________________________________________________________________________ 5
ATTENUATION ABSOLUTE ACCURACY
(ALL STATES)
MAX2027 toc08
FREQUENCY (MHz)
ABSOLUTE ACCURACY (dB)
350300200 250150100
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
50 400
ATTENUATION RELATIVE ACCURACY
(ALL STATES)
MAX2027 toc09
FREQUENCY (MHz)
RELATIVE ACCURACY (dB)
350300200 250150100
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
50 400
NOISE FIGURE vs. FREQUENCY
MAX2027 toc10
FREQUENCY (MHz)
NOISE FIGURE (dB)
350300200 250150100
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
2.0
50 400
TA = +25°C
TA = +85°C
TA = -40°C
OUTPUT P-1dB vs. FREQUENCY
MAX2027 toc11
FREQUENCY (MHz)
OUTPUT P-1dB (dBm)
350300250200150100
18
19
20
21
22
23
17
50 400
TA = +85°C
TA = -40°C
TA = +25°C
OUTPUT P-1dB vs. FREQUENCY
MAX2027 toc12
FREQUENCY (MHz)
OUTPUT P-1dB (dBm)
350300250200150100
18
19
20
21
22
23
17
50 400
VCC = +5.25V
VCC= +4.75V
VCC = +5V
OUTPUT IP3 vs. FREQUENCY
MAX2027 toc13
FREQUENCY (MHz)
OIP3 (dBm)
350300250200150100
32
34
36
38
40
30
50 400
TA = -40°C
TA = +85°C
TA = +25°C
P
RF1
= P
RF2
= 5dBm
AT OUTPUT, ∆f = 1MHz
OUTPUT IP3 vs. FREQUENCY
MAX2027 toc14
FREQUENCY (MHz)
OIP3 (dBm)
350300250200150100
32
34
36
38
40
30
50 400
VCC = +5.25V
VCC = +5V
VCC = +4.75V
P
RF1
= P
RF2
= 5dBm
AT OUTPUT, ∆f = 1MHz
Typical Operating Characteristics (continued)
(Typical application circuit, VCC= 5.0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), P
OUT
= 5dBm, R1= 825Ω, TA= +25°C, unless
otherwise noted.)
Page 6
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
6 _______________________________________________________________________________________
INPUT IP3 vs. ATTENUATION STATE
MAX2027 toc15
ATTENUATION STATE
IIP3 (dBm)
20161284
20
30
25
35
40
45
15
024
fIN = 400MHz
fIN = 200MHz
fIN = 50MHz
P
RF1
= P
RF2
= 5dBm
AT OUTPUT, ∆f = 1MHz
2ND HARMONIC vs. FREQUENCY
MAX2027 toc16
FREQUENCY (MHz)
HARMONIC (dBc)
350300250200150100
-55
-50
-45
-40
-35
-30
-60
50 400
TA = +85°C
TA = -40°C
TA = +25°C
2ND HARMONIC vs. FREQUENCY
MAX2027 toc17
FREQUENCY (MHz)
HARMONIC (dBc)
350300250200150100
-55
-50
-45
-40
-35
-30
-60
50 400
VCC = +5V
VCC = +5.25V
VCC = +4.75V
O1P2 vs. FREQUENCY
(F1 + F2)
MAX2027 toc18
FREQUENCY (MHz)
O1P2 (dBm)
350300250200150100
39
41
43
45
49
47
51
37
50 400
TA = +25°C
TA = +85°C
TA = -40°C
P
RF1
= P
RF2
= 5dBm
AT OUTPUT, ∆f = 1MHz
O1P2 vs. FREQUENCY
(F1 + F2)
MAX2027 toc19
FREQUENCY (MHz)
O1P2 (dBm)
350300250200150100
39
41
43
45
49
47
51
37
50 400
VCC = +4.75V
VCC = +5.0V
VCC = +5.25V
P
RF1
= P
RF2
= 5dBm
AT OUTPUT, ∆f = 1MHz
3RD HARMONIC vs. FREQUENCY
MAX2027 toc20
FREQUENCY (MHz)
HARMONIC (dBc)
350300250200150100
-80
-75
-70
-65
-60
-55
-85
50 400
TA = +25°C
TA = +85°C
TA = -40°C
3RD HARMONIC vs. FREQUENCY
MAX2027 toc21
FREQUENCY (MHz)
HARMONIC (dBc)
350300250200150100
-80
-75
-70
-65
-60
-55
-85
50 400
VCC = +4.75V
VCC = +5.25V
VCC = +5V
Typical Operating Characteristics (continued)
(Typical application circuit, VCC= 5.0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), P
OUT
= 5dBm, R1= 825Ω, TA= +25°C, unless
otherwise noted.)
Page 7
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
_______________________________________________________________________________________ 7
Detailed Description
The MAX2027 is a high-performance, digitally controlled variable-gain amplifier for use in applications
from 50MHz to 400MHz.
The MAX2027 incorporates a digital attenuator with a
23dB selectable attenuation range followed by a fixedgain, high-linearity amplifier. The attenuator is digitally
controlled through five logic lines: B0–B4. This on-chip
attenuator provides up to 23dB of attenuation with
±0.05dB state-to-state accuracy. The fixed-gain amplifier utilizes negative feedback to achieve high stability,
gain, linearity, and wide bandwidth.
Applications Information
Input and Output Matching
The MAX2027 incorporates on-chip input and output
matching for operation below 250MHz. Use a DC-blocking capacitor value of 1000pF for pins 3, 12, and 18 (see
Figure 1). For operation above 250MHz, external matching improves performance. Table 1 and Table 2 provide
recommended components for device operation.
Digitally Controlled Attenuator
The digital attenuator is controlled through five logic
lines: B0, B1, B2, B3, and B4. Table 3 lists the attenuation settings. The input and output of this attenuator
require external DC-blocking capacitors. This attenuator insertion loss is 2dB when the attenuator is set to
0dB (B0 = B1 = B2 = B3 = B4 = 0).
Pin Description
PIN NAME FUNCTION
1, 2, 11 V
CC
Power Supply. Bypass to GND with capacitors as close to the pin as possible as shown in the typical
application circuit (Figure 1).
3 RF_IN
Signal Input. See the typical application circuit for recommended component values. Requires an
external DC-blocking capacitor.
4, 5, 16, 17,
19, 20, EP
GND
Ground. Use low-inductance layout techniques on PC board. Solder the exposed pad evenly to the
board ground plane.
6–10 B4–B0 Gain-Control Bits. See Table 3 for gain setting.
12 RF_OUT
Signal Output. Requires an external pullup choke inductor (52mA typical current) to V
CC
along with a
DC-blocking capacitor (Figure 1).
13 I
SET
Connect an 825Ω resistor from I
SET
to GND.
14 I
BIAS
Amplifier Bias. Connect to AMPIN (pin 15) through a choke inductor (0.3mA typ).
15 AMP
IN
Amplifier Input. Requires a DC-coupling capacitor to allow biasing.
18
Attenuator Output. Requires an external DC-blocking capacitor.
Table 1. Suggested Components of
Typical Application Circuit
FREQUENCY
COMPONENT
VALUE SIZE
L3, L4 11nH 0603
300MHz
C8, C9 6.8pF 0603
L3, L4 8.7nH 0603
400MHz
C8, C9 5pF 0603
Table 2. Suggested Matching
Components
ATTN
OUT
COMPONENT VALUE SIZE
C1, C3, C4 1000pF 0603
C2, C5 100pF 0603
C6, C7 0.1µF 0603
C10 0.047µF 0603
R1 825Ω ±1% 0603
R2–R6 47kΩ 0603
L1 330nH 0805
L2 680nH 1008
Page 8
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
8 _______________________________________________________________________________________
Fixed-Gain Amplifier
The MAX2027 integrates a fixed-gain amplifier in a negative feedback topology. This fixed-gain amplifier is
optimized for a frequency range of operation from
50MHz to 400MHz with a high-output third-order intercept point (OIP3). The bias current is chosen to optimize the IP3of the amplifier. When R1 is 825Ω, the
current consumption is 60mA while exhibiting a typical
35dBm output IP3.
Choke Inductor
The fixed-gain amplifier output port requires an external
pullup choke inductor to VCC. At the input, connect a
bias inductor of 330nH from AMPIN(pin 15) to I
BIAS
(pin 14). At the output, connect a 680nH choke inductor
from RF_OUT (pin 12) to VCC(pin 11) to provide bias
current to the amplifier.
Layout Considerations
A properly designed PC board is an essential part of
any RF/microwave circuit. Keep RF signal lines as short
as possible to reduce losses, radiation, and induc-
tance. For the best performance, route the ground pin
traces directly to the exposed pad under the package.
The PC board exposed pad must be connected to the
ground plane of the PC board. It is suggested that multiple vias be used to connect this pad to the lower level
ground planes. This method provides a good RF/thermal
conduction path for the device. Solder the exposed pad
on the bottom of the device package to the PC board.
The MAX2027 Evaluation Kit can be used as a reference for board layout. Gerber files are available upon
request at www.maxim-ic.com.
Power-Supply Bypassing
Proper voltage-supply bypassing is essential for highfrequency circuit stability. Bypass each VCCpin with a
0.1µF and 100pF capacitor. Connect the 100pF capacitor
as close to VCCpins as possible.
Exposed Pad RF/Thermal Considerations
The exposed paddle (EP) of the MAX2027’s 20-pin
TSSOP-EP package provides a low thermal-resistance
path to the die. It is important that the PC board on
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
RF IN
V
CC
C
2
R
2
R
3
B2
B3
B4
12
11
9
10
RF OUT
V
CC
B0
B1
MAX2027
ATTENUATION
LOGIC
CONTROL
AMP
BIAS
V
CC
C8*
L
3
*
C
7
C
6
C
5
L
2
L
1
C
1
R
4
R
5R6
CONTROL
INPUTS
L4*
ATTN
OUT
AMP
IN
*OPTIONAL COMPONENTS: USE TO IMPROVE HIGHER FREQUENCY MATCHING
I
BIAS
I
SET
C
3
C9*
C
10
C
4
R
1
EXPOSED
PADDLE
Figure 1. Typical Application Circuit
Page 9
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
_______________________________________________________________________________________ 9
which the MAX2027 is mounted be designed to conduct heat from the EP. In addition, provide the EP with
a low-inductance path to electrical ground. The EP
must be soldered to a ground plane on the PC board,
either directly or through an array of plated via holes.
ATTENUATION (dB)
B4
B3*
B0
(1dB)
0 00000
1 00001
2 00010
3 00011
4 00100
5 00101
6 00110
7 00111
8 01000
9 01001
10 01010
11 01011
12 01100
13 01101
14 01110
15 01111
16 1 X 000
17 1 X 001
18 1 X 010
19 1 X 011
20 1 X 100
21 1 X 101
22 1 X 110
23 1 X 111
Table 3. Attenuation Setting vs. GainControl Bits
*Enabling B4 disables B3, and the minimum attenuation is 16dB.
Chip Information
TRANSISTOR COUNT: 325
(16dB)
(8dB)B2(4dB)B1(2dB)
Page 10
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
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.
10 ____________________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.
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
TSSOP 4.4mm BODY.EPS
PACKAGE OUTLINE, TSSOP, 4.40 MM BODY
EXPOSED PAD
21-0108
1
D
1
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