MAXIM MAX2027EUP-T

19-2601; Rev 1; 2/04
IF Digitally Controlled Variable-Gain Amplifier
Features
The MAX2027 high-performance, digitally controlled
variable-gain amplifier is designed for use from 50MHz
to 400MHz.
♦ 50MHz to 400MHz Frequency Range
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.
♦ Output IP3: 35dBm (at All Gain Settings)
♦ Variable Gain: -8dB to +15dB
♦ Noise Figure: 4.7dB at Maximum Gain
♦ Digitally Controlled Gain with 1dB Resolution and
±0.05dB State-to-State Accuracy
Ordering Information
PART
MAX2027EUP-T
TEMP RANGE
PIN-PACKAGE
-40°C to +85°C
20 TSSOP-EP*
*EP = exposed pad.
Pin Configuration/
Functional Diagram
Applications
Cellular Base Stations
Receiver Gain Control
VCC
1
VCC
2
RF_IN
3
18 ATTNOUT
GND
4
17 GND
GND
5
16 GND
B4
6
15 AMPIN
B3
7
Transmitter Gain Control
Broadband Systems
Automatic Test Equipment
Terrestrial Links
B2
8
B1
9
B0 10
20 GND
MAX2027
ATTENUATION
LOGIC
CONTROL
AMP
BIAS
19 GND
14 IBIAS
13 ISET
12 RF_OUT
11 VCC
________________________________________________________________ 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
MAX2027
General Description
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
ABSOLUTE MAXIMUM RATINGS
All Pins Input Voltage (except AMPIN, IBIAS, and ISET)
to GND................................................................-0.3V to +5.5V
Input Voltage Levels (B0–B4).....................-0.3V to (VCC + 0.5V)
Input Voltage Levels (AMPIN and IBIAS)................-0.3V to +1.5V
Input Voltage Levels (ISET) ....................................-0.3V to +1.0V
RF Input Signal .................................................................20dBm
RF Output Signal...............................................................22dBm
Continuous Power Dissipation (TA = +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
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.
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. R1 = 825Ω, TA = -40°C to +85°C. Typical values are at VCC = +5V and TA = +25°C, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
4.75
5.00
5.25
V
75
SUPPLY
Supply Voltage
VCC
Supply Current
ICC
60
ISET Current
ISET
0.9
mA
mA
5
Bits
CONTROL INPUTS/OUTPUTS
Control Bits
Parallel
Input Logic High
(Note 3)
2
Input Logic Low
Input Leakage Current
2
-1.2
_______________________________________________________________________________________
V
0.6
V
+1.2
µA
IF Digitally Controlled Variable-Gain Amplifier
(Typical application circuit without matching, VCC = +4.75V to +5.25V, GND = 0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), R1 =
825Ω, POUT = 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
Frequency Range
fR
Gain
G
Noise Figure
NF
Minimum Reverse Isolation
CONDITIONS
MIN
TYP
50
No attenuation
15.5
MAX
UNITS
400
MHz
dB
Max gain
4.7
dB
Max gain
22
dB
20.6
dBm
Output 1dB Compression Point
P1dB
Max gain
2nd-Order Output Intercept Point
OIP2
f1 + f2, f1 = 50MHz, f2 = 51MHz, 5dBm/tone
3rd-Order Output Intercept Point
OIP3
All gain conditions, 5dBm/tone
2nd Harmonic
3rd Harmonic
42
dBm
34.7
dBm
2fIN
-44
dBc
3fIN
-68
dBc
RF Gain-Control Range
23
dB
Gain-Control Resolution
1
dB
Attenuation Absolute Accuracy
Compared to the ideal expected
attenuation
0.15/
-0.05
dB
Attenuation Relative Accuracy
Between adjacent states
±0.05
dB
Gain Drift Over Temperature
TA = -40°C to +85°C
±0.1
dB
Gain Flatness Over 50MHz BW
Peak-to-peak for all settings,
FCENTER = 75MHz
0.1
Peak-to-peak for all settings,
FCENTER = 200MHz
0.2
dB
Attenuator Switching Time
50% control to 90% RF
40
ns
Input Return Loss
fR = 50MHz to 250MHz, all gain conditions
15
dB
Output Return Loss
fR = 50MHz to 250MHz, all gain conditions
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.
_______________________________________________________________________________________
3
MAX2027
AC ELECTRICAL CHARACTERISTICS
Typical Operating Characteristics
(Typical application circuit, VCC = 5.0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), POUT = 5dBm, R1 = 825Ω, TA = +25°C, unless
otherwise noted.)
VCC = 5.25V
58
56
VCC = 4.75V
10
15
20
25
52
5
20
35
50
65
80
50
100
150
TEMPERATURE (°C)
200
250
300
25
350
50
400
100
150
200
35
MAX2027 toc04
30
REVERSE ISOLATION (dB)
15
10
5
0
-5
25
20
15
10
-10
-15
5
50
100
150
200
250
300
350
400
50
100
FREQUENCY (MHz)
300
350
400
MAX2027 toc07
17
16
TA = -40°C
GAIN (dB)
TA = +25°C
14
TA = +85°C
13
250
18
MAX2027 toc06
17
15
200
GAIN vs. FREQUENCY
GAIN vs. FREQUENCY
16
150
FREQUENCY (MHz)
18
VCC = 4.75V, 5.0V, AND 5.25V
15
14
13
12
12
11
11
10
10
50
100
150
200
250
300
FREQUENCY (MHz)
350
400
250
300
FREQUENCY (MHz)
REVERSE ISOLATION vs. FREQUENCY
20
GAIN (dB)
20
FREQUENCY (MHz)
GAIN vs. RF FREQUENCY
(ALL STATES)
GAIN (dB)
15
35
35
-40 -25 -10
10
30
30
54
4
5
MAX2027 toc05
60
INPUT RETURN LOSS (dB)
VCC = 5.0V
62
MAX2027 toc03
5
64
OUTPUT RETURN LOSS (dB)
66
0
MAX2027 toc02
0
MAX2027 toc01
68
OUTPUT RETURN LOSS
vs. RF FREQUENCY (ALL STATES)
INPUT RETURN LOSS
vs. RF FREQUENCY (ALL STATES)
SUPPLY CURRENT vs. TEMPERATURE
SUPPLY CURRENT (mA)
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
50
100
150
200
250
300
350
400
FREQUENCY (MHz)
_______________________________________________________________________________________
350
400
IF Digitally Controlled Variable-Gain Amplifier
0.8
0.4
0.2
0
-0.2
-0.4
0.6
6.5
0.4
0.2
0
-0.2
-0.4
5.0
4.5
4.0
-0.6
3.0
-0.8
2.5
-1.0
-1.0
200
250
300
350
400
2.0
50
100
FREQUENCY (MHz)
150
200
250
300
350
50
100
200
250
300
350
400
OUTPUT P-1dB vs. FREQUENCY
22
OUTPUT P-1dB (dBm)
TA = +85°C
TA = +25°C
20
19
MAX2027 toc12
23
MAX2027 toc11
22
21
150
FREQUENCY (MHz)
OUTPUT P-1dB vs. FREQUENCY
23
OUTPUT P-1dB (dBm)
400
FREQUENCY (MHz)
21
VCC = +5.25V
20
VCC= +4.75V
19
VCC = +5V
TA = -40°C
18
18
17
17
100
150
200
250
300
350
400
50
100
FREQUENCY (MHz)
OIP3 (dBm)
TA = +25°C
34
40
300
350
400
TA = +85°C
PRF1 = PRF2 = 5dBm
AT OUTPUT, ∆f = 1MHz
38
OIP3 (dBm)
38
36
250
OUTPUT IP3 vs. FREQUENCY
PRF1 = PRF2 = 5dBm
AT OUTPUT, ∆f = 1MHz
TA = -40°C
200
FREQUENCY (MHz)
OUTPUT IP3 vs. FREQUENCY
40
150
VCC = +5.25V
36
34
VCC = +4.75V
VCC = +5V
32
MAX2027 toc14
50
MAX2027 toc13
150
TA = -40°C
3.5
-0.8
100
TA = +25°C
5.5
-0.6
50
TA = +85°C
6.0
NOISE FIGURE (dB)
RELATIVE ACCURACY (dB)
0.6
NOISE FIGURE vs. FREQUENCY
7.0
MAX2027 toc09
0.8
ABSOLUTE ACCURACY (dB)
1.0
MAX2027 toc08
1.0
ATTENUATION RELATIVE ACCURACY
(ALL STATES)
MAX2027 toc10
ATTENUATION ABSOLUTE ACCURACY
(ALL STATES)
32
30
30
50
100
150
200
250
300
FREQUENCY (MHz)
350
400
50
100
150
200
250
300
350
400
FREQUENCY (MHz)
_______________________________________________________________________________________
5
MAX2027
Typical Operating Characteristics (continued)
(Typical application circuit, VCC = 5.0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), POUT = 5dBm, R1 = 825Ω, TA = +25°C, unless
otherwise noted.)
Typical Operating Characteristics (continued)
(Typical application circuit, VCC = 5.0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), POUT = 5dBm, R1 = 825Ω, TA = +25°C, unless
otherwise noted.)
2ND HARMONIC vs. FREQUENCY
fIN = 400MHz
fIN = 50MHz
fIN = 200MHz
TA = +25°C
-45
-50
-55
15
8
12
16
20
24
100
150
200
250
300
350
400
VCC = +5V
50
100
MAX2027 toc18
49
TA = -40°C
TA = +25°C
PRF1 = PRF2 = 5dBm
AT OUTPUT, ∆f = 1MHz
49
O1P2 (dBm)
45
43
200
VCC = +4.75V
47
VCC = +5.0V
45
43
41
41
39
39
37
VCC = +5.25V
37
50
100
150
200
250
300
350
400
50
100
FREQUENCY (MHz)
3RD HARMONIC vs. FREQUENCY
250
300
350
400
3RD HARMONIC vs. FREQUENCY
-60
VCC = +4.75V
VCC = +5V
HARMONIC (dBc)
TA = -40°C TA = +25°C
-65
-70
200
-55
MAX2027 toc20
-60
150
FREQUENCY (MHz)
-55
TA = +85°C
-75
-80
-65
-70
VCC = +5.25V
-75
-80
-85
-85
50
100
150
200
250
300
FREQUENCY (MHz)
350
400
250
300
FREQUENCY (MHz)
51
TA = +85°C
47
150
O1P2 vs. FREQUENCY
(F1 + F2)
PRF1 = PRF2 = 5dBm
AT OUTPUT, ∆f = 1MHz
51
O1P2 (dBm)
VCC = +4.75V
FREQUENCY (MHz)
O1P2 vs. FREQUENCY
(F1 + F2)
HARMONIC (dBc)
-50
-60
50
ATTENUATION STATE
6
-45
-55
-60
4
VCC = +5.25V
TA = +85°C
20
0
-40
MAX2027 toc19
25
TA = -40°C
MAX2027 toc21
30
-40
-35
HARMONIC (dBc)
35
-35
HARMONIC (dBc)
40
-30
MAX2027 toc16
MAX2027 toc15
PRF1 = PRF2 = 5dBm
AT OUTPUT, ∆f = 1MHz
2ND HARMONIC vs. FREQUENCY
-30
MAX2027 toc17
INPUT IP3 vs. ATTENUATION STATE
45
IIP3 (dBm)
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
50
100
150
200
250
300
350
400
FREQUENCY (MHz)
_______________________________________________________________________________________
350
400
IF Digitally Controlled Variable-Gain Amplifier
PIN
NAME
FUNCTION
Power Supply. Bypass to GND with capacitors as close to the pin as possible as shown in the typical
application circuit (Figure 1).
1, 2, 11
VCC
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
12
RF_OUT
Gain-Control Bits. See Table 3 for gain setting.
Signal Output. Requires an external pullup choke inductor (52mA typical current) to VCC along with a
DC-blocking capacitor (Figure 1).
13
ISET
Connect an 825Ω resistor from ISET to GND.
14
IBIAS
Amplifier Bias. Connect to AMPIN (pin 15) through a choke inductor (0.3mA typ).
15
AMPIN
18
ATTNOUT
Amplifier Input. Requires a DC-coupling capacitor to allow biasing.
Attenuator Output. Requires an external DC-blocking capacitor.
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).
Table 1. Suggested Components of
Typical Application Circuit
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
Table 2. Suggested Matching
Components
FREQUENCY
300MHz
400MHz
COMPONENT
VALUE
SIZE
L3, L4
11nH
0603
C8, C9
6.8pF
0603
L3, L4
8.7nH
0603
C8, C9
5pF
0603
_______________________________________________________________________________________
7
MAX2027
Pin Description
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
VCC
1
C7
C1
C2
2
20
MAX2027
19
L3*
3
C8*
VCC
18
EXPOSED
PADDLE
4
R6
R5
C9*
L4*
RF IN
R4
R3
R2
ATTNOUT
17
5
16
6
15
C3
L1
B4
B3
CONTROL
INPUTS
B2
B1
B0
7
8
9
10
ATTENUATION
LOGIC
CONTROL
AMP
BIAS
14
13
AMPIN
IBIAS
ISET
C10
R1
12
RF OUT
C4
11
L2
VCC
*OPTIONAL COMPONENTS: USE TO IMPROVE HIGHER FREQUENCY MATCHING
C5
C6
Figure 1. Typical Application Circuit
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 IP3 of 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 IBIAS
(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-
8
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 VCC pin with a
0.1µF and 100pF capacitor. Connect the 100pF capacitor
as close to VCC pins 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
_______________________________________________________________________________________
IF Digitally Controlled Variable-Gain Amplifier
ATTENUATION (dB)
B4
B3*
(16dB) (8dB)
Chip Information
TRANSISTOR COUNT: 325
B2
(4dB)
B1
(2dB)
B0
(1dB)
0
0
0
0
0
0
1
0
0
0
0
1
2
0
0
0
1
0
3
0
0
0
1
1
4
0
0
1
0
0
5
0
0
1
0
1
6
0
0
1
1
0
7
0
0
1
1
1
8
0
1
0
0
0
9
0
1
0
0
1
10
0
1
0
1
0
11
0
1
0
1
1
12
0
1
1
0
0
13
0
1
1
0
1
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
*Enabling B4 disables B3, and the minimum attenuation is 16dB.
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.
_______________________________________________________________________________________
9
MAX2027
Table 3. Attenuation Setting vs. GainControl Bits
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
MAX2027
IF Digitally Controlled Variable-Gain Amplifier
PACKAGE OUTLINE, TSSOP, 4.40 MM BODY
EXPOSED PAD
21-0108
D
1
1
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.