MAXIM MAX2057ETX

19-3510; Rev 0; 1/05
KIT
ATION
EVALU
LE
B
A
IL
A
AV
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
The MAX2057 general-purpose, high-performance variable-gain amplifier (VGA) is designed to operate in the
1700MHz to 2500MHz frequency range*. This device
features 15.5dB of gain, 6dB of noise figure, and an output 1dB compression point of 23.8dBm. The MAX2057
also provides an exceptionally high OIP3 level of
37dBm, which is maintained over the entire attenuation
range. In addition, the on-chip analog attenuators yield
infinite control and high attenuation accuracy over
selectable 21dB or 42dB control ranges. Each of these
features makes the MAX2057 an ideal VGA for
DCS/PCS, cdma2000™, W-CDMA, and PHS/PAS transmitter and power amplifier AGC circuits.
The MAX2057 is pin compatible with the MAX2056
800MHz to 1000MHz VGA, making this family of amplifiers ideal for applications where a common PC board
layout is used for both frequency bands.
The MAX2057 operates from a single +5V supply and is
available in a compact 36-pin thin QFN package (6mm
x 6mm x 0.8mm) with an exposed paddle. Electrical
performance is guaranteed over the extended -40°C to
+85°C temperature range.
Features
♦ 1700MHz to 2500MHz RF Frequency Range*
♦ 37dBm Constant OIP3 (Over All Gain Settings)
♦ 23.8dBm Output 1dB Compression Point
♦ 15.5dB Typical Gain at Maximum Gain Setting
♦ 0.5dB Gain Flatness Over 100MHz Bandwidth
♦ 6dB Noise Figure at Maximum Gain Setting (Using
1 Attenuator)
♦ Two Gain-Control Ranges: 21dB and 42dB
♦ Analog Gain Control
♦ Single +5V Supply Voltage
♦ Pin Compatible with MAX2056, 800MHz to
1000MHz RF VGA
♦ External Current-Setting Resistors Provide Option
for Operating VGA in Reduced-Power/ReducedPerformance Mode
♦ Lead-Free Package Available
*Note: Operation beyond this range is possible, but has not been
characterized.
Applications
DCS 1800/PCS 1900 2G and 2.5G EDGE BaseStation Transmitters and Power Amplifiers
cdmaOne™, cdma2000, Base-Station
Transmitters and Power Amplifiers
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
PKG
CODE
UMTS/W-CDMA and Other 3G Base-Station
Transmitters and Power Amplifiers
MAX2057ETX
-40°C to +85°C
36 Thin QFN-EP**
T3666-2
6mm x 6mm
PHS/PAS Base-Station Transmitters and Power
Amplifiers
MAX2057ETX-T
-40°C to +85°C
36 Thin QFN-EP**
T3666-2
6mm x 6mm
Transmitter Gain Control
MAX2057ETX+D
-40°C to +85°C
36 Thin QFN-EP**
T3666-2
6mm x 6mm
MAX2057ETX+TD -40°C to +85°C
36 Thin QFN-EP**
T3666-2
6mm x 6mm
Receiver Gain Control
Broadband Systems
Automatic Test Equipment
Digital and Spread-Spectrum Communication
Systems
Microwave Terrestrial Links
cdmaOne is a trademark of CDMA Development Group.
cdma2000 is a registered trademark of Telecommunications
Industry Association.
**EP = Exposed paddle.
+ = Lead (Pb) free.
D = Dry pack.
-T = Tape-and-reel package.
Pin Configuration/Functional Diagram appear at end of data
sheet.
________________________________________________________________ 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
MAX2057
General Description
MAX2057
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
ABSOLUTE MAXIMUM RATINGS
VCC to GND ...........................................................-0.3V to +5.5V
VCNTL to GND (with VCC applied) .............................0V to 4.75V
Current into VCNTL pin (VCC grounded) .............................40mA
All Other Pins to GND.................................-0.3V to (VCC + 0.3V)
RF Input Power (IN, IN_A, ATTN_OUT, OUT_A) ...........+20dBm
RF Input Power (AMP_IN)...............................................+12dBm
θJA (natural convection)...................................................35°C/W
θJA (1m/s airflow) .............................................................31°C/W
θJA (2.5m/s airflow) ..........................................................29°C/W
θJC (junction to exposed paddle) ....................................10°C/W
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°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
(VCC = +4.75V to +5.25V, no RF signals applied, all input and output ports terminated with 50Ω, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +5.0V, TA = +25°C, unless otherwise noted.)
PARAMETER
CONDITIONS
Supply Voltage
Supply Current
R1 = 1.2kΩ, R2 = 2kΩ (Note 1)
RSET1 Current
R1 = 1.2kΩ (Note 1)
RSET2 Current
R1 = 2kΩ (Note 1)
Gain-Control Voltage Range
(Note 2)
MIN
TYP
MAX
UNITS
4.75
5
5.25
V
180
230
mA
0.6
mA
1.0
Gain-Control Pin Input Resistance VCNTL = 1V to 4.5V
250
mA
1
4.5
500
V
kΩ
AC ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit with one attenuator connected, VCC = +4.75V to +5.25V, TA = -40°C to +85°C, unless otherwise noted.
Typical values are at VCC = +5.0V, R1 = 1.2kΩ, R2 = 2kΩ, POUT = +5dBm, fIN = 2100MHz, VCNTL = 1V, 50Ω system impedance,
second attenuator is not connected, TA = +25°C, unless otherwise noted.) (Note 3)
PARAMETER
CONDITIONS
Frequency Range
Gain
TA = +25°C
TA = +25°C to -40°C
Maximum Gain Variation
13.5
TYP
15.5
VCNTL = 1V
+0.9
VCNTL = 1.8V
+0.41
VCNTL = 2.6V
+0.09
VCNTL = 3.5V
-0.16
VCNTL = 1V
TA = +25°C to +85°C
-1
VCNTL = 1.8V
-0.56
VCNTL = 2.6V
-0.32
VCNTL = 3.5V
+0.1
Reverse Isolation
Noise Figure
MIN
1700
37
(Note 4)
Output 1dB Compression Point
MAX
UNITS
2500
MHz
17.5
dB
dB
dB
6
dB
+23.8
dBm
Output 2nd-Order Intercept Point
From maximum gain to 15dB attenuation, measured at f1
+ f2 (Note 5)
+64
dBm
Output 3rd-Order Intercept Point
From maximum gain to 15dB attenuation (Note 5)
+37
dBm
2
_______________________________________________________________________________________
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
(Typical Operating Circuit with one attenuator connected, VCC = +4.75V to +5.25V, TA = -40°C to +85°C, unless otherwise noted.
Typical values are at VCC = +5.0V, R1 = 1.2kΩ, R2 = 2kΩ, POUT = +5dBm, fIN = 2100MHz, VCNTL = 1V, 50Ω system impedance,
second attenuator is not connected, TA = +25°C, unless otherwise noted.) (Note 3)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Output 3rd-Order Intercept Point
Variation Over Temperature
TA = +25°C to +85°C
-0.83
TA = +25°C to -40°C
-0.6
2nd Harmonic
From maximum gain to 15dB attenuation, POUT = +5dBm
-65
dBc
3rd Harmonic
From maximum gain to 15dB attenuation, POUT = +5dBm
-83
dBc
One attenuator
17
20.7
Two attenuators
34
42.4
RF Gain-Control Range
fRF = 1.7GHz to 2.2GHz,
VCNTL = 1V to 4.5V
RF Gain-Control Slope
VCNTL = 1.8V to 3.5V
Maximum RF Gain-Control Slope
Maximum slope vs. gain-control voltage
Gain Flatness Over
100MHz Bandwidth
dB
dB
-10
dB/V
-15.2
dB/V
Peak-to-peak for all settings
0.5
dB
Attenuator Switching Time
15dB attenuation change (Note 6)
500
ns
Attenuator Insertion Loss
Second attenuator (IN_A, OUT_A)
2.2
dB
Input Return Loss
Entire band, all gain settings
18
dB
Output Return Loss
Entire band, all gain settings
15
dB
Group Delay
Input/output 50Ω lines de-embedded
300
ps
Group Delay Flatness Over
100MHz Bandwidth
Peak to peak
20
ps
Group Delay Change vs. Gain
Control
VCNTL = 1V to 4V
-70
ps
Insertion Phase Change vs. Gain
Control
VCNTL = 1V to 4V
50
degrees
Note 1: Total supply current reduces as R1 and R2 are increased.
Note 2: Operating outside this range for extended periods may affect device reliability. Limit pin input current to 40mA when VCC
is not present.
Note 3: All limits include external component losses, unless otherwise noted.
Note 4: Noise figure increases by approximately 1dB for every 1dB of gain reduction.
Note 5: f1 = 2100MHz, f2 = 2101MHz, +5dBm/tone at OUT.
Note 6: Switching time is measured from 50% of the control signal to when the RF output settles to ±1dB.
_______________________________________________________________________________________
3
MAX2057
AC ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
One Attenuator Configuration
(Typical Application Circuit with one attenuator connected, VCC = +5.0V, R1 = 1.2kΩ, R2 = 2kΩ, fIN = 2100MHz, maximum gain
setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT
INPUT RETURN LOSS
OUTPUT RETURN LOSS
vs. SUPPLY VOLTAGE
vs. RF FREQUENCY
vs. RF FREQUENCY
TA = +25°C
160
TA = -40°C
150
4.750
TA = +85°C
20
25
30
TA = +25°C
5.000
5.125
5.250
MAX2057 toc03
20
TA = +25°C
TA = +85°C
25
30
40
1500
1700
1900
2100
2300
2500
1500
1700
1900
2100
2300
RF FREQUENCY (MHz)
RF FREQUENCY (MHz)
GAIN vs. GAIN-CONTROL VOLTAGE
GAIN vs. RF FREQUENCY
REVERSE ISOLATION
vs. RF FREQUENCY
GAIN (dB)
TA = +25°C
TA = +85°C
15
TA = +25°C
TA = +85°C
13
TA = +85°C
REVERSE ISOLATION (dB)
17
MAX2057 toc06
TA = -40°C
2500
40
MAX2057 toc05
MAX2057 toc04
19
0
35
TA = +25°C
TA = -40°C
30
11
25
9
1.5
2.0
2.5
3.0
3.5
4.0
1500
1700
1900
2100
2300
RF FREQUENCY (MHz)
INPUT RETURN LOSS
vs. RF FREQUENCY
OUTPUT RETURN LOSS
vs. RF FREQUENCY
9dB, 12dB, 15dB, 18dB
GAIN REDUCTION
10
15
MAX GAIN
20
25
30
6dB GAIN REDUCTION
35
5
40
1700
1900
2100
RF FREQUENCY (MHz)
2300
2500
2300
2500
MAXIMUM GAIN
15
10
15
20
MAX GAIN, 3dB, 6dB, 9dB, 12dB,
15dB, AND 18dB GAIN REDUCTION
25
5
0
30
-5
40
1500
2100
10
35
3dB GAIN REDUCTION
1900
20
MAX2057 toc08
5
1700
GAIN vs. RF FREQUENCY
0
OUTPUT RETURN LOSS (dB)
0
1500
2500
RF FREQUENCY (MHz)
VCNTL (V)
MAX2057 toc07
1.0
GAIN (dB)
-10
MAX2057 toc09
-5
4
TA = -40°C
15
SUPPLY VOLTAGE (V)
15
5
10
35
40
4.875
TA = -40°C
GAIN (dB)
TA = -40°C
15
5
35
20
10
10
0
OUTPUT RETURN LOSS (dB)
180
170
5
INPUT RETURN LOSS (dB)
190
MAX2057 toc02
TA = +85°C
SUPPLY CURRENT (mA)
0
MAX2057 toc01
200
INPUT RETURN LOSS (dB)
MAX2057
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
18dB GAIN REDUCTION
-10
1500
1700
1900
2100
RF FREQUENCY (MHz)
2300
2500
1500
1700
1900
2100
RF FREQUENCY (MHz)
_______________________________________________________________________________________
2300
2500
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
One Attenuator Configuration
(Typical Application Circuit with one attenuator connected, VCC = +5.0V, R1 = 1.2kΩ, R2 = 2kΩ, fIN = 2100MHz, maximum gain
setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25°C, unless otherwise noted.)
REVERSE ISOLATION
vs. RF FREQUENCY
NOISE FIGURE vs. RF FREQUENCY
35
MAXIMUM GAIN
7.0
6.5
6.0
TA = +25°C
5.5
30
5.0
25
4.5
TA = -40°C
2100
2300
1700
OUTPUT IP3 vs. RF FREQUENCY
36
2500
2300
1500
1700
MAX2057 toc13
VCC = 5.25V
38
TA = +25°C
36
2300
2500
41
38
VCC = 5.00V
TA = +25°C
35
32
TA = +85°C
29
TA = -40°C
26
32
2100
INPUT IP3 vs. ATTENUATION
VCC = 4.75V
34
1900
RF FREQUENCY (MHz)
OUTPUT IP3 vs. RF FREQUENCY
TA = +85°C
34
2100
40
OUTPUT IP3 (dBm)
TA = -40°C
38
1900
RF FREQUENCY (MHz)
RF FREQUENCY (MHz)
40
VCC = 5.00V
VCC = 5.25V
4.0
1500
2500
INPUT IP3 (dBm)
1900
5.5
4.5
MAX2057 toc14
1700
6.0
5.0
4.0
1500
VCC = 4.75V
6.5
MAX2057 toc15
40
20
OUTPUT IP3 (dBm)
7.5
NOISE FIGURE (dB)
45
MAX2057 toc12
TA = +85°C
7.0
50
NOISE FIGURE (dB)
REVERSE ISOLATION (dB)
7.5
8.0
MAX2057 toc11
18dB GAIN REDUCTION
55
NOISE FIGURE vs. RF FREQUENCY
8.0
MAX2057 toc10
60
32
23
20
30
1500
1700
1900
2100
2300
2500
1500
1700
RF FREQUENCY (MHz)
32
30
10
ATTENUATION (dB)
15
20
15
20
75
MAX2057 toc17
35
34
TA = +85°C
70
OUTPUT IP2 (dBm)
36
65
60
TA = +25°C
TA = -40°C
55
50
45
32
5
10
OUTPUT IP2 vs. RF FREQUENCY
33
0
5
ATTENUATION (dB)
37
OUTPUT IP3 (dBm)
OUTPUT IP3 (dBm)
TA = -40°C
TA = +85°C
0
2500
OUTPUT IP3 vs. OUTPUT POWER
36
34
2300
38
MAX2057 toc16
TA = +25°C
38
2100
RF FREQUENCY (MHz)
OUTPUT IP3 vs. ATTENUATION
40
1900
MAX2057 toc18
30
-6
-3
0
3
6
9
OUTPUT POWER PER TONE (dBm)
12
1500
1700
1900
2100
2300
2500
RF FREQUENCY (MHz)
_______________________________________________________________________________________
5
MAX2057
Typical Operating Characteristics (continued)
Typical Operating Characteristics (continued)
One Attenuator Configuration
(Typical Application Circuit with one attenuator connected, VCC = +5.0V, R1 = 1.2kΩ, R2 = 2kΩ, fIN = 2100MHz, maximum gain
setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25°C, unless otherwise noted.)
OUTPUT IP2 vs. ATTENUATION
70
MAX2057 toc20
MAX2057 toc19
VCC = 4.75V
VCC = 5.00V
70
INPUT IP2 vs. ATTENUATION
70
65
MAX2057 toc21
OUTPUT IP2 vs. RF FREQUENCY
75
TA = +85°C
60
INPUT IP2 (dBm)
65
VCC = 5.25V
55
60
55
TA = -40°C
TA = +25°C
50
TA = +25°C
TA = -40°C
60
45
45
55
40
1500
1700
1900
2100
2300
2500
0
5
RF FREQUENCY (MHz)
10
10
15
OUTPUT P1dB vs. RF FREQUENCY
MAX2057 toc22
26
TA = +25°C
VCC = 5.25V
25
OUTPUT P1dB (dBm)
OUTPUT P1dB (dBm)
TA = -40°C
24
23
5
ATTENUATION (dB)
OUTPUT P1dB vs. RF FREQUENCY
25
0
20
15
ATTENUATION (dB)
26
TA = +85°C
22
21
VCC = 5.00V
24
23
VCC = 4.75V
22
21
20
20
1500
1700
1900
2100
RF FREQUENCY (MHz)
6
65
MAX2057 toc23
50
OUTPUT IP2 (dBm)
TA = +85°C
OUTPUT IP2 (dBm)
MAX2057
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
2300
2500
1500
1700
1900
2100
2300
RF FREQUENCY (MHz)
_______________________________________________________________________________________
2500
20
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
Two Attenuator Configuration
(Typical Application Circuit with two attenuators connected, VCC = +5.0V, R1 = 1.2kΩ, R2 = 2kΩ, fIN = 2100MHz, maximum gain
setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25°C, unless otherwise noted.)
INPUT RETURN LOSS
vs. RF FREQUENCY
OUTPUT RETURN LOSS
vs. RF FREQUENCY
10
TA = -40°C
15
20
25
TA = +85°C
30
TA = +25°C
MAX2057 toc25
5
OUTPUT RETURN LOSS (dB)
5
35
10
TA = -40°C
15
20
TA = +25°C
25
30
35
40
40
1500
1700
1900
2100
2300
2500
1500
1700
RF FREQUENCY (MHz)
TA = -40°C
15
GAIN (dB)
TA = +85°C
-5
2300
17
MAX2057 toc26
TA = -40°C
TA = +25°C
2100
2500
GAIN vs. RF FREQUENCY
GAIN vs. GAIN-CONTROL VOLTAGE
5
1900
RF FREQUENCY (MHz)
15
GAIN (dB)
TA = +85°C
MAX2057 toc27
INPUT RETURN LOSS (dB)
0
MAX2057 toc24
0
13
TA = +25°C
-15
11
-25
9
TA = +85°C
7
-35
1.0
1.5
2.0
2.5
VCNTL (V)
3.0
3.5
4.0
1500
1700
1900
2100
2300
2500
RF FREQUENCY (MHz)
_______________________________________________________________________________________
7
MAX2057
Typical Operating Characteristics
Typical Operating Characteristics (continued)
Two Attenuator Configuration
(Typical Application Circuit with two attenuators connected, VCC = +5.0V, R1 = 1.2kΩ, R2 = 2kΩ, fIN = 2100MHz, maximum gain
setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25°C, unless otherwise noted.)
REVERSE ISOLATION
vs. RF FREQUENCY
INPUT RETURN LOSS
vs. RF FREQUENCY
TA = +25°C
MAXIMUM GAIN
6dB GAIN REDUCTION
10
15
20
25
30
12dB, 18dB, 24dB, 30dB
GAIN REDUCTION
35
30
2100
2500
2300
1700
1900
2100
GAIN vs. RF FREQUENCY
REVERSE ISOLATION
vs. RF FREQUENCY
70
5
0
-5
-10
1500
30dB GAIN REDUCTION
60
50
40
10.0
1900
2100
2500
2300
1500
1700
1900
2100
OUTPUT IP3 vs. RF FREQUENCY
8.0
TA = +25°C
TA = -40°C
2500
2300
1500
1700
MAX2057 toc34
TA = +25°C
1900
TA = +85°C
70
TA = -40°C
TA = +85°C
34
TA = +25°C
65
60
TA = -40°C
55
50
30
45
1500
1700
1900
2100
RF FREQUENCY (MHz)
2300
2500
1500
2100
RF FREQUENCY (MHz)
75
OUTPUT IP2 (dBm)
OUTPUT IP3 (dBm)
8.5
OUTPUT IP2 vs. RF FREQUENCY
32
8
9.0
RF FREQUENCY (MHz)
40
36
TA = +85°C
6.0
RF FREQUENCY (MHz)
38
2500
9.5
6.5
20
1700
2300
7.0
MAXIMUM GAIN
30dB GAIN REDUCTION
-25
2100
10.5
7.5
30
1500
1900
NOISE FIGURE vs. RF FREQUENCY
-15
-20
1700
11.0
NOISE FIGURE (dB)
REVERSE ISOLATION (dB)
10
30
RF FREQUENCY (MHz)
80
MAX2057 toc31
MAXIMUM GAIN
6dB, 12dB, 18dB, 24dB,
30dB GAIN REDUCTION
25
2500
2300
RF FREQUENCY (MHz)
15
20
40
1500
RF FREQUENCY (MHz)
20
MAXIMUM GAIN
15
MAX2057 toc35
1900
MAX2057 toc32
1700
10
35
40
1500
MAX2057 toc30
5
MAX2057 toc33
TA = -40°C
35
5
0
OUTPUT RETURN LOSS (dB)
40
MAX2057 toc29
MAX2057 toc28
TA = +85°C
OUTPUT RETURN LOSS
vs. RF FREQUENCY
0
INPUT RETURN LOSS (dB)
REVERSE ISOLATION (dB)
45
GAIN (dB)
MAX2057
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
1700
1900
2100
2300
2500
RF FREQUENCY (MHz)
_______________________________________________________________________________________
2300
2500
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
PIN
NAME
1, 3, 4, 6, 7,
9, 10, 12, 14,
18, 19,
21–24, 27,
28, 30, 31,
33, 34, 36
FUNCTION
GND
2
OUT_A
5, 13, 16, 25,
32
VCC
Power Supply. Bypass each pin to GND with capacitors as shown in the Typical Application Circuit.
Place capacitors as close to the pin as possible.
8
IN_A
Second-Attenuator Input. Internally matched to 50Ω over the operating frequency band. Connect to a
50Ω RF source through a DC-blocking capacitor if greater than 21dB of gain-control range is
required. No connection is required if the second attenuator is not used.
11
VCNTL
Analog Gain-Control Input. Limit voltages applied to this pin to a 1V to 4.5V range when VCC is
present to ensure device reliability.
15
RSET1
First-Stage Amplifier Bias-Current Setting. Connect to GND through a 1.2kΩ resistor.
17
RSET2
Second-Stage Amplifier Bias-Current Setting. Connect to GND through a 2kΩ resistor.
20
OUT
RF Output. Internally matched to 50Ω over the operating frequency band. Requires a DC-blocking
capacitor and a shunt-matching capacitor.
26
AMP_IN
Amplifier Input. Internally matched to 50Ω over the operating frequency band. Connect to ATTN_OUT
through a DC-blocking capacitor.
29
ATTN_OUT
Attenuator Output. Internally matched to 50Ω over the operating frequency band. Connect to AMP_IN
through a DC-blocking capacitor.
35
IN
RF Input. Internally matched to 50Ω over the operating frequency band. Connect to a 50Ω RF source
through a DC-blocking capacitor if the second attenuator is not used.
Exposed
Paddle
GND
Ground. Connect to the board’s ground plane using low-inductance layout techniques.
Second-Attenuator Output. Internally matched to 50Ω over the operating frequency band. Connect to
IN through a DC-blocking capacitor if greater than 21dB of gain-control range is required. No
connection is required if the second attenuator is not used.
Exposed Paddle Ground Plane. This paddle affects RF performance and provides heat dissipation.
This paddle MUST be soldered evenly to the board’s ground plane for proper operation.
_______________________________________________________________________________________
9
MAX2057
Pin Description
MAX2057
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
VCC
GND
GND
C1
IN_A
GND
GND
GND
GND
VCC
GND
26
EP
3
25
MAX2057
4
24
5
23
22
6
ATTENUATION
CONTROL
CIRCUITRY
7
21
8
20
9
19
11
GND
VCNTL
10
12
13
14
15
16
17
GND
AMP_IN
VCC
VCC
C6
C13
GND
GND
GND
GND
C7
RF
OUTPUT
OUT
GND
0.06in LONG FR4 50Ω
TRANSMISSION LINE
C17
18
GND
VCC
C5
28
2
RSET2
C2
29
27
VCC
GND
30
RSET1
VCC
31
1
GND
GND
32
33
VCC
OUT_A
34
GND
GND
35
GND
IN
GND
36
ATTN_OUT
C4
C3
RF INPUT*
R1
VGC
+
-
VCC
C10
C15
VCC
C9
C8
R2
C14
*NOTE: CONNECT THE INPUT ACCORDING TO THE SOLID BOLD LINE IF ONE ATTENUATOR
IS USED. CONNECT THE INPUT ACCORDING TO THE BROKEN LINE IF TWO ATTENUATORS ARE USED.
Figure 1. Typical Application Circuit
Detailed Description
The MAX2057 general-purpose, high-performance VGA
with analog gain control is designed to interface with
50Ω systems operating in the 1700MHz to 2500MHz
frequency range.
The MAX2057 integrates two attenuators to provide
21dB or 42dB of precision analog gain control, as well
10
as a two-stage amplifier that has been optimized to
provide high gain, high IP3, low noise figure, and low
power consumption. The bias current of each amplifier
stage can be adjusted by individual external resistors
to further reduce power consumption for applications
that do not require high linearity.
______________________________________________________________________________________
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
DESIGNATION
VALUE
TYPE
C1, C3, C5, C7, C10
22pF
Microwave capacitors
(0402)
C2, C4, C6, C8, C9
1000pF
Microwave capacitors
(0402)
C13, C14, C15
0.1µF
Microwave capacitors
(0603)
C17
0.75pF
Microwave capacitor
(0402)
R1
1.2kΩ
±1% resistor (0402)
R2
2kΩ
±1% resistor (0402)
Applications Information
Analog Attenuation Control
A single input voltage at the VCNTL pin adjusts the gain
of the MAX2057. Up to 21dB of gain-control range is
provided through a single attenuator. At the maximum
gain setting, each attenuator’s insertion loss is approximately 2.2dB. With the single attenuator at the maximum
gain setting, the device provides a nominal 15.5dB of
cascaded gain and 6dB of cascaded noise figure.
If a larger gain-control range is desired, a second onchip attenuator can be connected in the signal path to
provide an additional 21dB of gain-control range. With
the second attenuator connected at the maximum gain
setting, the device typically exhibits 13.3dB of cascaded gain. Note that the VCNTL pin simultaneously adjusts
both on-chip attenuators.
The VCNTL input voltage drives a high-impedance load
(>250kΩ). It is suggested that a current-limiting resistor
be included in series with this connection to limit the
input current to less than 40mA should the control voltage be applied when VCC is not present. A series resistor of greater than 200Ω will provide complete
protection for 5V control voltage ranges. Limit VCNTL
input voltages to a 1.0V to 4.5V range when VCC is
present to ensure the reliability of the device.
Amplifier Bias Current
The MAX2057 integrates a two-stage amplifier to simultaneously provide high gain and high IP3. Optimal performance is obtained when R1 and R2 are equal to
1.2kΩ and 2kΩ, respectively. The typical supply current
is 180mA and the typical output IP3 is 37dBm under
these conditions.
Increasing R1 and R2 from the nominal values of 1.2kΩ
and 2kΩ reduces the bias current of each amplifier
stage, which reduces the total power consumption and
IP3 of the device. This feature can be utilized to further
decrease power consumption for applications that do
not require high IP3.
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 inductance. For best performance, route the ground-pin
traces directly to the exposed pad underneath the
package. This pad MUST be connected to the ground
plane of the board by using multiple vias under the
device to provide the best RF and thermal conduction
path. Solder the exposed pad on the bottom of the
device package to a PC board exposed pad.
Power-Supply Bypassing
Proper voltage-supply bypassing is essential for highfrequency circuit stability. Bypass each VCC pin with
capacitors placed as close to the device as possible.
Place the smallest capacitor closest to the device. Refer
to the MAX2057 evaluation kit data sheet for more details.
Exposed Paddle RF and Thermal
Considerations
The EP of the MAX2057’s 36-pin thin QFN-EP package
provides a low-thermal-resistance path to the die. It is
important that the PC board on which the IC is mounted
be designed to conduct heat from this contact. In addition, the EP provides a low-inductance RF ground path
for the device.
The EP MUST be soldered to a ground plane on the PC
board either directly or through an array of plated via
holes. Soldering the pad to ground is also critical for
efficient heat transfer. Use a solid ground plane wherever possible.
______________________________________________________________________________________
11
MAX2057
Table 1. Typical Application Circuit
Component Values
GND
1
OUT_A
2
GND
GND
IN
GND
GND
VCC
GND
GND
ATTN_OUT
GND
Pin Configuration/
Functional Diagram
36
35
34
33
32
31
30
29
28
Chip Information
TRANSISTOR COUNT: 5191
PROCESS: BiCMOS
Package Information
27 GND
For the latest package outline information, go to
www.maxim-ic.com/packages.
26 AMP_IN
EP
3
25 VCC
MAX2057
GND
4
24 GND
VCC
5
23 GND
GND
6
GND
22 GND
ATTENUATION
CONTROL
CIRCUITRY
7
21 GND
12
13
14
15
16
RSET1
VCC
17
18
GND
11
RSET2
10
GND
19 GND
VCC
GND 9
GND
20 OUT
VCNTL
IN_A 8
GND
MAX2057
1700MHz to 2500MHz Variable-Gain
Amplifier with Analog Gain Control
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.
12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.