View MAX2056_370510.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-3508; Rev 0; 2/05
KIT ATION EVALU E AILABL AV
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control
General Description Features
800MHz to 1000MHz RF Frequency Range* 39dBm Constant OIP3 (Over All Gain Settings) 23.5dBm Output 1dB Compression Point 15.5dB Typical Gain at Maximum Gain Setting 0.15dB Gain Flatness Over 100MHz Bandwidth 4.5dB Noise Figure at Maximum Gain Setting (Using 1 Attenuator) Two Gain-Control Ranges: 22dB and 44dB Analog Gain Control Single +5V Supply Voltage Pin Compatible with MAX2057, 1700MHz to 2500MHz 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.
MAX2056
The MAX2056 general-purpose, high-performance variable-gain amplifier (VGA) is designed to operate in the 800MHz to 1000MHz frequency range*. This device features 15.5dB of gain, 4.5dB of noise figure, and an output 1dB compression point of 23.5dBm. The MAX2056 also provides an exceptionally high OIP3 level of 39dBm, which is maintained over the entire attenuation range. In addition, the on-chip analog attenuators yield infinite control and high attenuation accuracy over selectable 22dB or 44dB control ranges. Each of these features makes the MAX2056 an ideal VGA for cellular band GSM, cdma2000(R), W-CDMA, and iDEN(R) transmitter and power amplifier AGC circuits. The MAX2056 is pin compatible with the MAX2057 1700MHz to 2500MHz VGA, making this family of amplifiers ideal for applications where a common PC board layout is used for both frequency bands. The MAX2056 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 pad. Electrical performance is guaranteed over the extended -40C to +85C temperature range.
Applications
GSM 850/GSM 900 2G and 2.5G EDGE BaseStation Transmitters and Power Amplifiers Cellular cdmaOneTM, cdma2000, and Integrated Digital Enhanced Network (iDEN) Base-Station Transmitters and Power Amplifiers W-CDMA 850MHz and Other 3G Base-Station Transmitters and Power Amplifiers Transmitter Gain Control Receiver Gain Control Broadband Systems Automatic Test Equipment Digital and Spread-Spectrum Communication Systems Microwave Terrestrial Links
Ordering Information
PART MAX2056ETX MAX2056ETX-T MAX2056ETX+D MAX2056ETX+TD TEMP RANGE -40C to +85C -40C to +85C -40C to +85C -40C to +85C PIN-PACKAGE PKG CODE
36 Thin QFN-EP** T3666-2 6mm x 6mm 36 Thin QFN-EP** T3666-2 6mm x 6mm 36 Thin QFN-EP** T3666-2 6mm x 6mm 36 Thin QFN-EP** T3666-2 6mm x 6mm
**EP = Exposed paddle. + = Lead (Pb) free. D = Dry pack. T = Tape-and-reel package. Pin Configuration/Functional Diagram appears at end of data sheet.
cdmaOne is a trademark of CDMA Development Group. cdma2000 is a registered trademark of Telecommunications Industry Association. iDEN is a registered trademark of Motorola, Inc.
________________________________________________________________ Maxim Integrated Products
1
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.
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
ABSOLUTE MAXIMUM RATINGS
VCC to GND ...........................................................-0.3V to +5.5V VCNTL to GND (with VCC applied)................................0 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 JA (natural convection)...................................................35C/W JA (1m/s airflow) .............................................................31C/W JA (2.5m/s airflow) ..........................................................29C/W JC (junction to exposed paddle) ....................................10C/W Operating Temperature Range ...........................-40C to +85C Storage Temperature Range .............................-65C to +150C Junction Temperature ......................................................+150C Lead Temperature (soldering, 10s) .................................+300C
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 50, TA = -40C to +85C, unless otherwise noted. Typical values are at VCC = +5.0V, TA = +25C, unless otherwise noted.)
PARAMETER Supply Voltage Supply Current RSET1 Current RSET2 Current Gain-Control Voltage Range Gain-Control Pin Input Resistance R1 = 1.2k, R2 = 3.92k (Note 1) R1 = 1.2k (Note 1) R2 = 3.92k (Note 1) (Note 2) VCNTL = 1V to 4.5V 1.0 250 500 CONDITIONS MIN 4.75 TYP 5 136 1 0.33 4.5 MAX 5.25 167 UNITS V mA mA mA V k
AC ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit with one attenuator connected, VCC = +4.75V to +5.25V, TA = -40C to +85C, unless otherwise noted. Typical values are at VCC = +5.0V, R1 = 1.2k, R2 = 3.92k, POUT = +5dBm, fIN = 900MHz, VCNTL = 1V, 50 system impedance, second attenuator is not connected, TA = +25C, unless otherwise noted.) (Note 3)
PARAMETER Frequency Range Gain TA = +25C VCNTL = 1V TA = +25C to -40C Maximum Gain Variation TA = +25C to +85C VCNTL = 1.8V VCNTL = 2.6V VCNTL = 3.5V VCNTL = 1V VCNTL = 1.8V VCNTL = 2.6V VCNTL = 3.5V Reverse Isolation Noise Figure Output 1dB Compression Point Output 2nd-Order Intercept Point Output 3rd-Order Intercept Point From maximum gain to 15dB attenuation, measured at f1 + f2 (Note 5) From maximum gain to 15dB attenuation (Note 5) (Note 4) CONDITIONS MIN 800 15.5 +0.82 +0.26 +0.25 -0.18 -0.51 -0.11 -0.16 +0.09 29 4.5 +23.5 +54 +39 dB dB dBm dBm dBm dB TYP MAX 1000 UNITS MHz dB
2
_______________________________________________________________________________________
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control
AC ELECTRICAL CHARACTERISTICS (continued)
(Typical Operating Circuit with one attenuator connected, VCC = +4.75V to +5.25V, TA = -40C to +85C, unless otherwise noted. Typical values are at VCC = +5.0V, R1 = 1.2k, R2 = 3.92k, POUT = +5dBm, fIN = 900MHz, VCNTL = 1V, 50 system impedance, second attenuator is not connected, TA = +25C, unless otherwise noted.) (Note 3)
PARAMETER Output 3rd-Order Intercept Point Variation Over Temperature 2nd Harmonic 3rd Harmonic RF Gain-Control Range RF Gain-Control Slope Maximum RF Gain-Control Slope Gain Flatness Over 100MHz Bandwidth Attenuator Switching Time Attenuator Insertion Loss Input Return Loss Output Return Loss Group Delay Group Delay Flatness Over 100MHz Bandwidth Group Delay Change vs. Gain Control Insertion Phase Change vs. Gain Control Maximum slope vs. gain-control voltage Peak-to-peak for all settings 15dB attenuation change (Note 6) Second attenuator (IN_A, OUT_A) Entire band, all gain settings Entire band, all gain settings Input/output 50 lines de-embedded Peak to peak VCNTL = 1V to 4V VCNTL = 1V to 4V CONDITIONS TA = +25C to +85C TA = +25C to -40C From maximum gain to 15dB attenuation, POUT = +5dBm From maximum gain to 15dB attenuation, POUT = +5dBm fRF = 800MHz to 1000MHz, VCNTL = 1V to 4.5V One attenuator Two attenuators 18.3 36.6 MIN TYP -0.46 +1.35 -55 -68 22.3 44.6 -10.7 -17.2 0.15 500 1.7 15 15 600 100 100 20 MAX UNITS dB dBc dBc dB dB/V dB/V dB ns dB dB dB ps ps ps degrees
MAX2056
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 = 900MHz, f2 = 901MHz, +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
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
Typical Operating Characteristics
One Attenuator Configuration
(Typical Application Circuit with one attenuator connected, VCC = +5.0V, R1 = 1.2k, R2 = 3.92k, fIN = 900MHz maximum gain setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. VCC
MAX2056 toc01
INPUT RETURN LOSS vs. RF FREQUENCY
MAX2056 toc02
OUTPUT RETURN LOSS vs. RF FREQUENCY
MAX2056 toc03
160 150 SUPPLY CURRENT (mA) 140 130 120 110 100 4.750 TA = +85C TA = +25C TA = -40C
0 5 INPUT RETURN LOSS (dB) 10 15 20 25 30 TA = +85C TA = +25C TA = -40C
0 5 OUTPUT RETURN LOSS (dB) TA = +25C 10 TA = -40C 15 20 25 30 TA = +85C
4.875
5.000 VCC (V)
5.125
5.250
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
GAIN vs. VCNTL
MAX2056 toc04
GAIN vs. RF FREQUENCY
TA = -40C 16 15 GAIN (dB) 14 13 12 11 20 700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz) TA = +25C
MAX2056 toc05
REVERSE ISOLATION vs. RF FREQUENCY
MAX2056 toc06 MAX2056 toc09
20 TA = -40C 15 10 GAIN (dB) 5 0 -5 -10 1.0 1.5 2.0 2.5 VCNTL (V) 3.0 3.5 TA = +25C TA = +85C
17
35 TA = +85C ISOLATION (dB) 30
TA = +25C 25
TA = -40C
TA = +85C
4.0
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
INPUT RETURN LOSS vs. RF FREQUENCY
MAX2056 toc07
OUTPUT RETURN LOSS vs. RF FREQUENCY
MAX2056 toc08
GAIN vs. RF FREQUENCY
23 18 13 MAXIMUM GAIN
0 5 INPUT RETURN LOSS (dB) 10 MAXIMUM GAIN 15 20 25 21dB GAIN REDUCTION 30
0 5 OUTPUT RETURN LOSS (dB) 10 MAXIMUM GAIN 15 20
GAIN (dB)
8 3 -2 -7
25 30
21dB GAIN REDUCTION
-12 -17
22dB GAIN REDUCTION 700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
4
_______________________________________________________________________________________
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
Typical Operating Characteristics (continued)
One Attenuator Configuration
(Typical Application Circuit with one attenuator connected, VCC = +5.0V, R1 = 1.2k, R2 = 3.92k, fIN = 900MHz maximum gain setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25C, unless otherwise noted.)
REVERSE ISOLATION vs. RF FREQUENCY
21dB GAIN REDUCTION 55 REVERSE ISOLATION (dB) 50 45 40 35 30 25 20 700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz) MAXIMUM GAIN 2 800 850 900 950 1000 RF FREQUENCY (MHz) 2 800 850 900 950 1000 RF FREQUENCY (MHz) NOISE FIGURE (dB)
MAX2056 toc10
NOISE FIGURE vs. RF FREQUENCY
MAX2056 toc11
NOISE FIGURE vs. RF FREQUENCY
MAX2056 toc12
60
7 TA = +85C
7
6
TA = +25C
6 NOISE FIGURE (dB) VCC = 5.25V 5
5
4
4 VCC = 4.75V 3 VCC = 5.00V
3
TA = -40C
OUTPUT IP3 vs. FREQUENCY
MAX2056 toc13
OUTPUT IP3 vs. FREQUENCY
MAX2056 toc14
INPUT IP3 vs. ATTENUATION
MAX2056 toc15
41 TA = -40C 40 OUTPUT IP3 (dBm)
41
50 45 TA = +25C INPUT IP3 (dBm) 40 35 30 25 20 TA = -40C TA = +85C
40 OUTPUT IP3 (dBm) VCC = 5.00V 39
VCC = 5.25V
39
38
TA = +25C TA = +85C
38 VCC = 4.75V 37
37
36 800 850 900 950 1000 RF FREQUENCY (MHz)
36 800 850 900 950 1000 RF FREQUENCY (MHz)
0
5
10
15
20
25
ATTENUATION (dB)
OUTPUT IP3 vs. ATTENUATION
MAX2056 toc16
OUTPUT IP3 vs. OUTPUT POWER
MAX2056 toc17
OUTPUT IP2 vs. RF FREQUENCY
TA = -40C 60 OUTPUT IP2 (dBm) TA = +25C
MAX2056 toc18
50 45 OUTPUT IP3 (dBm) 40 35 TA = -40C 30 25 20 0 5 10 15 20 TA = +85C TA = +25C
40
65
38 OUTPUT IP3 (dBm)
55 TA = +85C
36
50
34
45
32 25 -6 -3 0 3 6 9 12 ATTENUATION (dB) OUTPUT POWER PER TONE (dBm)
40 800 850 900 950 1000 RF FREQUENCY (MHz)
_______________________________________________________________________________________
5
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
Typical Operating Characteristics (continued)
One Attenuator Configuration
(Typical Application Circuit with one attenuator connected, VCC = +5.0V, R1 = 1.2k, R2 = 3.92k, fIN = 900MHz maximum gain setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25C, unless otherwise noted.)
OUTPUT IP2 vs. RF FREQUENCY
MAX2056 toc19
INPUT IP2 vs. ATTENUATION
MAX2056 toc20
OUTPUT IP2 vs. ATTENUATION
MAX2056 toc21
70
65 TA = +85C 60 INPUT IP2 (dBm) 55 50 TA = +25C 45 40 35 TA = -40C
65 60 OUTPUT IP2 (dBm) 55 50 TA = +85C 45 40 35 TA = -40C
65 OUTPUT IP2 (dBm)
VCC = 5.00V VCC = 4.75V
TA = +25C
60
55 VCC = 5.25V 50
45 800 850 900 950 1000 RF FREQUENCY (MHz)
0
5
10
15
20
25
0
5
10
15
20
25
ATTENUATION (dB)
ATTENUATION (dB)
OUTPUT P1dB vs. RF FREQUENCY
MAX2056 toc22
OUTPUT P1dB vs. RF FREQUENCY
MAX2056 toc23
26 25 OUTPUT P1dB (dBm) 24 23 22 21 20 800 850 900 950 TA = +85C TA = -40C
26 25 OUTPUT P1dB (dBm) 24 23 VCC = 5.00V 22 21 20 VCC = 4.75V VCC = 5.25V
TA = +25C
1000
800
850
900
950
1000
RF FREQUENCY (MHz)
RF FREQUENCY (MHz)
6
_______________________________________________________________________________________
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
Typical Operating Characteristics
Two Attenuator Configuration
(Typical Application Circuit with two attenuators connected, VCC = +5.0V, R1 = 1.2k, R2 = 3.92k, fIN = 900MHz maximum gain setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25C, unless otherwise noted.) OUTPUT RETURN LOSS INPUT RETURN LOSS vs. RF FREQUENCY GAIN vs. VCNTL vs. RF FREQUENCY
MAX2056 toc25 MAX2056 toc24
5 INPUT RETURN LOSS (dB) 10 15 20 25 30 35 TA = +85C TA = +25C TA = -40C
15 5 TA = +25C TA = +85C -5 -15 -25 -35
TA = -40C
OUTPUT RETURN LOSS (dB)
5 10 15 TA = -40C 20 TA = +85C 25 30
40 700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
GAIN (dB)
TA = +25C
1.0
1.5
2.0
2.5 3.0 VCNTL (V)
3.5
4.0
GAIN vs. RF FREQUENCY
MAX2056 toc27
REVERSE ISOLATION vs. RF FREQUENCY
TA = +85C
MAX2056 toc28
INPUT RETURN LOSS vs. RF FREQUENCY
MAX2056 toc29
17
35
0 5 INPUT RETURN LOSS (dB) 10 MAXIMUM GAIN 15 20 25 42dB GAIN REDUCTION
15
TA = -40C ISOLATION (dB) 30 TA = -40C TA = +25C
GAIN (dB)
13 TA = +25C 11 TA = +85C 9
25
7 700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
20 700 900 1100 1300 1500 RF FREQUENCY (MHz)
30 700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
OUTPUT RETURN LOSS vs. RF FREQUENCY
MAX2056 toc30
GAIN vs. RF FREQUENCY
MAXIMUM GAIN 15 5
MAX2056 toc31
0 5 OUTPUT RETURN LOSS (dB) 10 MAXIMUM GAIN 15 20 25 30 42dB GAIN REDUCTION
25
GAIN (dB)
-5 -15 -25 -35 44dB GAIN REDUCTION -45
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
700 800 900 1000 1100 1200 1300 1400 1500 RF FREQUENCY (MHz)
_______________________________________________________________________________________
MAX2056 toc26
0
0
7
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
Typical Operating Characteristics (continued)
Two Attenuator Configuration
(Typical Application Circuit with two attenuators connected, VCC = +5.0V, R1 = 1.2k, R2 = 3.92k, fIN = 900MHz maximum gain setting, POUT = +5dBm, linearity measured at POUT = +5dBm/tone, TA = +25C, unless otherwise noted.)
REVERSE ISOLATION vs. RF FREQUENCY
MAX2056 toc32
NOISE FIGURE vs. RF FREQUENCY
MAX2056 toc33
80 42dB GAIN REDUCTION 70 REVERSE ISOLATION (dB) 60 50 40 30 MAXIMUM GAIN 20 700 900 1100 1300
9 TA = +85C
8 NOISE FIGURE (dB)
7
TA = +25C
6
5 TA = -40C 4 1500 800 850 900 950 1000 RF FREQUENCY (MHz) RF FREQUENCY (MHz)
OUTPUT IP3 vs. RF FREQUENCY
MAX2056 toc34
OUTPUT IP2 vs. RF FREQUENCY
MAX2056 toc35
41 TA = -40C
65
40 OUTPUT IP3 (dBm)
60 OUTPUT IP2 (dBm)
TA = -40C
39
55 TA = +25C
38
TA = +25C TA = +85C
50
TA = +85C
37
45
36 800 850 900 950 1000 RF FREQUENCY (MHz)
40 800 850 900 950 1000 RF FREQUENCY (MHz)
8
_______________________________________________________________________________________
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control
Pin Description
PIN 1, 3, 4, 6, 7, 9, 10, 12, 14, 18, 19, 21-24, 27, 28, 30, 31, 33, 34, 36 2 5, 13, 16, 25, 32 8 NAME FUNCTION
MAX2056
GND
Ground. Connect to the board's ground plane using low-inductance layout techniques.
OUT_A
Second-Attenuator Output. Internally matched to 50 over the operating frequency band. Connect to IN through a DC-blocking capacitor if greater than 22dB of gain-control range is required. No connection is required if the second attenuator is not used. 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. Second-Attenuator Input. Internally matched to 50 over the operating frequency band. Connect to a 50 RF source through a DC-blocking capacitor if greater than 22dB of gain-control range is required. No connection is required if the second attenuator is not used. 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. First-Stage Amplifier Bias-Current Setting. Connect to GND through a 1.2k resistor. Second-Stage Amplifier Bias-Current Setting. Connect to GND through a 3.92k resistor. RF Output. Internally matched to 50 over the operating frequency band. Requires a DC-blocking capacitor. Amplifier Input. Internally matched to 50 over the operating frequency band. Connect to ATTN_OUT through a DC-blocking capacitor. Attenuator Output. Internally matched to 50 over the operating frequency band. Connect to AMP_IN through a DC-blocking capacitor. RF Input. Internally matched to 50 over the operating frequency band. Connect to a 50 RF source through a DC-blocking capacitor 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.
VCC
IN_A
11 15 17 20 26 29 35 Exposed Paddle
VCNTL RSET1 RSET2 OUT AMP_IN ATTN_OUT IN GND
_______________________________________________________________________________________
9
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
VCC
RF INPUT*
C3
C4
ATTN_OUT
GND
GND
GND
GND
GND
GND
VCC
IN
36 1 2
35
34
33
32
31
30
29
28 27 26
C5
GND OUT_A GND VCC GND VCC GND GND IN_A GND
GND AMP_IN VCC GND GND GND GND OUT GND
EP 3 MAX2056 4 5 6 7 8 9 10 GND 11 VCNTL 12 GND 13 VCC 14 GND 15 RSET1 16 VCC 17 RSET2 18 GND ATTENUATION CONTROL CIRCUITRY 24 23 22 21 20 19 25 C6
VCC C13
C2
C1
C7 RF OUTPUT
R1 VGC + C10 VCC VCC R2
C15
C9
C8
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 MAX2056 general-purpose, high-performance VGA with analog gain control is designed to interface with 50 systems operating in the 800MHz to 1000MHz frequency range. The MAX2056 integrates two attenuators to provide 22dB or 44dB 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 lowpower 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.
______________________________________________________________________________________
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control
Table 1. Typical Application Circuit Components Values
DESIGNATION C1, C3, C5, C10 C2, C4, C6, C8, C9 C7 C13, C14, C15 R1 R2 VALUE 47pF 3.9pF 0.1F 1.2k 3.92k TYPE Microwave capacitors (0402) Microwave capacitor (0402) Microwave capacitors (0603) 1% resistor (0402) 1% resistor (0402)
formance is obtained when R1 and R2 are equal to 1.2k and 3.92k, respectively. The typical supply current is 136mA and the typical output IP3 is 39dBm under these conditions. Increasing R1 and R2 from the nominal values of 1.2k and 3.92k 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.
MAX2056
1000pF Microwave capacitors (0402)
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.
Applications Information
Analog Attenuation Control
A single input voltage at the VCNTL pin adjusts the gain of the MAX2056. Up to 22dB of gain-control range is provided through a single attenuator. At the maximum gain setting, each attenuator's insertion loss is approximately 1.7dB. With the single attenuator at the maximum gain setting, the device provides a nominal 15.5dB of cascaded gain and 4.5dB 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 22dB of gain-control range. With the second attenuator connected at the maximum gain setting, the device typically exhibits 13.8dB of cascaded gain. Note that the VCNTL pin simultaneously adjusts both on-chip attenuators. The VCNTL input voltage drives a high-impedance load (>250k). 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 200 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.
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 MAX2056 evaluation kit data sheet for more details.
Exposed Paddle RF and Thermal Considerations
The EP of the MAX2056'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.
Amplifier Bias Current
The MAX2056 integrates a two-stage amplifier to simultaneously provide high gain and high IP3. Optimal per-
______________________________________________________________________________________
11
800MHz to 1000MHz Variable-Gain Amplifier with Analog Gain Control MAX2056
Pin Configuration/ Functional Diagram
ATTN_OUT GND GND GND GND GND GND
Chip Information
TRANSISTOR COUNT: 5723 PROCESS: BiCMOS
Package Information
For the latest package outline information, go to www.maxim-ic.com/packages.
27 GND 26 AMP_IN 25 VCC
VCC 32
IN
36 GND OUT_A GND GND VCC GND GND 1 2 3
35
34
33
31
30
29
28
EP
MAX2056 4 5 6 7 ATTENUATION CONTROL CIRCUITRY 24 GND 23 GND 22 GND 21 GND 20 OUT 19 GND 10 GND 11 VCNTL 12 GND 13 VCC 14 GND 15 RSET1 16 VCC 17 RSET2 18 GND
IN_A 8 GND 9
Thin QFN
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 (c) 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.

▲Up To Search▲

Price & Availability of MAX2056

	To Download MAX2056 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .