General Description
The MAX2065 high-linearity, analog/digital variable-gain amplifier (VGA) is designed to operate in the 50MHz to 1000MHz frequency range with two indepen-dent attenuators (see the Typical Application Circuit ).The digital attenuator is controlled as a slave peripheral using either the SPI?-compatible interface or a parallel bus with 31dB total adjustment range in 1dB steps. An added feature allows “rapid-fire” gain selection between each of four steps, preprogrammed by the user through the SPI-compatible interface. The 2-pin control allows the user to quickly access any one of four customized attenuation states without reprogram-ming the SPI bus. The analog attenuator is controlled using an external voltage or through the SPI-compatible interface using an on-chip 8-bit DAC.
Because each of the three stages has its own RF input and RF output, this component can be configured to either optimize NF (amplifier configured first), OIP3 (ampli-fier last), or a compromise of NF and OIP3. The device’s performance features include 22dB amplifier gain (ampli-fier only), 6.5dB NF at maximum gain (includes attenuator insertion losses), and a high OIP3 level of +42dBm. Each of these features makes the MAX2065 an ideal VGA for numerous receiver and transmitter applications.
In addition, the MAX2065 operates from a single +5V supply with full performance, or a single +3.3V supply with slightly reduced performance, and has an adjustable bias to trade current consumption for linearity performance. This device is available in a compact 40-pin thin QFN package (6mm x 6mm) with an exposed pad. Electrical performance is guaranteed over the extended temperature range (T C = -40°C to +85°C).
Applications
IF and RF Gain Stages
Temperature Compensation Circuits
Cellular Band WCDMA and cdma2000?Base Stations
GSM 850/GSM 900 EDGE Base Stations
WiMAX and LTE Base Stations and Customer Premise Equipment
Fixed Broadband Wireless Access Wireless Local Loop Military Systems
Video-on-Demand (VOD) and DOCSIS ?-Compliant EDGE QAM Modulation
Cable Modem Termination Systems (CMTS)
Features
?50MHz to 1000MHz RF Frequency Range
?Pin-Compatible Family Includes:
MAX2066 (Digital VGA)MAX2067 (Analog VGA)?+19.4dB (Typ) Maximum Gain
?0.5dB Gain Flatness Over 100MHz Bandwidth ?62dB Gain Range (31dB Analog + 31dB Digital)?Built-in DAC for Analog Attenuation Control ?Supports Four “Rapid-Fire” Preprogrammed Attenuator States
Quickly Access Any One of Four Customized Attenuation States Without Reprogramming the SPI Bus
Ideal for Fast-Attack, High-Level Blocker Protection Prevents ADC Overdrive Condition ?Excellent Linearity (Configured with Amplifier Last)
+42dBm OIP3+63dBm OIP2
+19dBm Output 1dB Compression Point -67dBc HD2-83dBc HD3?6.5dB Typical Noise Figure (NF)?Fast, 25ns Digital Switching
?Very Low Digital VGA Amplitude Overshoot/Undershoot ?Single +5V Supply (Optional +3.3V Operation)?External Current-Setting Resistors Provide Option
for Operating Device in Reduced-Power/Reduced-Performance Mode
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
________________________________________________________________Maxim Integrated Products
1
Ordering Information
19-3131; Rev 0; 3/08
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,or visit Maxim’s website at https://www.doczj.com/doc/936539359.html,.
+Denotes a lead-free package.*EP = Exposed pad.T = Tape and reel.
cdma2000 is a registered trademark of Telecommunications Industry Association.
DOCSIS and CableLabs are registered trademarks of Cable Television Laboratories, Inc. (CableLabs?).
SPI is a trademark of Motorola, Inc.
Pin Configuration appears at end of data sheet.
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 2_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
+3.3V SUPPLY DC ELECTRICAL CHARACTERISTICS
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.
Note 1:Based on junction temperature T J = T C + (θJC x V CC x I CC ). This formula can be used when the temperature of the exposed
pad is known while the device is soldered down to a printed-circuit board (PCB). See the Applications Information section for details. The junction temperature must not exceed +150°C.
Note 2:Junction temperature T J = T A + (θJA x V CC x I CC ). This formula can be used when the ambient temperature of the PCB is
known. The junction temperature must not exceed +150°C.
Note 3:Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a 4-layer
board. For detailed information on package thermal considerations, refer to https://www.doczj.com/doc/936539359.html,/thermal-tutorial .
Note 4:T C is the temperature on the exposed pad of the package. T A is the ambient temperature of the device and PCB.
VCC_ to GND ........................................................-0.3V to +5.5V VDD_LOGIC, DATA, CS , CLK, SER/PAR, VDAC_EN,
VREF_SELECT.....................................-0.3V to (VCC_ + 0.3V)STATE_A, STATE_B, D0–D4....................-0.3V to (VCC_ + 0.3V)AMP_IN, AMP_OUT, VREF_IN,
ANALOG_VCTRL................................-0.3V to (VCC_ + 0.3V)ATTEN1_IN, ATTEN1_OUT, ATTEN2_IN,
ATTEN2_OUT...................................................-1.2V to + 1.2V RSET to GND........................................................-0.3V to + 1.2V
RF Input Power (ATTEN1_IN, ATTEN1_OUT,
ATTEN2_IN, ATTEN2_OUT).......................................+20dBm RF Input Power (AMP_IN)...............................................+18dBm Continuous Power Dissipation (Note 1)...............................6.5W θJA (Notes 2, 3)..............................................................+38°C/W θJC (Note 3)...................................................................+10°C/W Operating Temperature Range (Note 4).....T C = -40°C to +85°C Maximum Junction Temperature.....................................+150°C Storage Temperature.........................................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°C
(Typical Application Circuit , V CC = +4.75V to +5.25V, T C = -40°C to +85°C. Typical values are at V CC = +5V and T = +25°C, unless otherwise noted.)
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
(Typical Application Circuit , V CC = +4.75 to +5.25V, HC mode with each attenuator set for maximum gain, 50MHz ≤f RF ≤1000MHz,T C = -40°C to +85°C. Typical values are at V CC = +5.0V, HC mode, P IN = -20dBm, f RF = 200MHz, and T C = +25o C, unless otherwise noted.) (Note 5)
+3.3V SUPPLY AC ELECTRICAL CHARACTERISTICS
(Typical Application Circuit , V CC = +3.0V to +3.6V, T C = -40°C to +85°C. Typical values are at V CC = +3.3V, HC mode with attenua-tors set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25o C, unless otherwise noted.) (Note 5)
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA
+5V SUPPLY AC ELECTRICAL CHARACTERISTICS (continued)
(Typical Application Circuit , V CC = +4.75 to +5.25V, HC mode with each attenuator set for maximum gain, 50MHz ≤f RF ≤1000MHz,T C = -40°C to +85°C. Typical values are at V CC = +5.0V, HC mode, P IN = -20dBm, f RF = 200MHz, and T C = +25o C, unless otherwise noted.) (Note 5)
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
_______________________________________________________________________________________5
+5V SUPPLY AC ELECTRICAL CHARACTERISTICS (continued)
(Typical Application Circuit , V CC = +4.75 to +5.25V, HC mode with each attenuator set for maximum gain, 50MHz ≤f RF ≤1000MHz,T C = -40°C to +85°C. Typical values are at V CC = +5.0V, HC mode, P IN = -20dBm, f RF = 200MHz, and T C = +25o C, unless otherwise noted.) (Note 5)
Note 6:Operating outside this range is possible, but with degraded performance of some parameters.Note 7:Guaranteed by design and characterization.
Note 8:It is advisable not to operate continuously the VGA RF input above +15dBm.
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 6_______________________________________________________________________________________
GAIN OVER DIGITAL ATTENUATOR SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)
G A I N (d B )
850
450
650
250
-8
2
1222-18
50
1050
DIGITAL ATTENUATOR RELATIVE ERROR vs. RF FREQUENCY
RF FREQUENCY (MHz)
R E L A T I V E E R R O R (d B )
850
450
650
250
-0.5000.501.00
-0.75
-0.250.250.75-1.00
50
1050
DIGITAL ATTENUATOR ABSOLUTE ERROR vs. RF FREQUENCY
RF FREQUENCY (MHz)
A B S O L U T E E R R O R (d B )
850450650250-0.5000.501.00-0.75-0.250.250.75-2.00
-1.25-1.50-1.70-1.0050
1050
INPUT MATCH OVER DIGITAL ATTENUATOR
SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)
I N P U T M A T C H (d B )
800
400
600
200
-15-10-5
0-30
-25
-200
1000
OUTPUT MATCH OVER DIGITAL ATTENUATOR
SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)
O U T P U T M A T C H (d B )
800
400
600
200
-15-10-50-30
-25-20
1000
REVERSE ISOLATION OVER DIGITAL ATTENUATOR SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)
R E V E R S E I S O L A T I O N (d B )
850
450
650
250
-50
-40
-30
-70
-60
50
1050
SUPPLY CURRENT vs. V CC
V CC (V)
S U P P L Y C U R R E N T (m A )
5.125
5.0004.875
110120
130
140150
1004.750
5.250
GAIN vs. RF FREQUENCY
RF FREQUENCY (MHz)
G A I N (d B )
850
450
650
250
15
1617
191820212214
50
1050
GAIN vs. RF FREQUENCY
RF FREQUENCY (MHz)
G A I N (d B )
850450650250151617
1918202122
14
501050
Typical Operating Characteristics
(V CC = +5.0V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
_______________________________________________________________________________________7
GAIN vs. ANALOG ATTENUATOR SETTING
DAC CODE
G A I N (d B )
12864
96
224160192
32
121722-18
72-3-8-130
256
GAIN vs. ANALOG ATTENUATOR SETTING
DAC CODE G A I N (d B )
128649622416019232121722-18
72-3-8-130256INPUT MATCH
vs. ANALOG ATTENUATOR SETTING
DAC CODE
I N P U T M A T C H (d B )
128649622416019232-50-30
-10
-15-20-250256
OUTPUT MATCH
vs. ANALOG ATTENUATOR SETTING
DAC CODE
O U T P U T M A T C H (d B )
12864
96
224160192
32
-50-30
-10-15-20-250
256
REVERSE ISOLATION OVER ANALOG ATTENUATOR SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)
R E V E R S E I S O L A T I O N (d B )
250
450
650
850
-30-70
-40
-50
-60
50
1050
S21 PHASE CHANGE
vs. ANALOG ATTENUATOR SETTING
DAC CODE
S 21 P H A S E C H A N G E (D E G )
32
64
96
12816022419280
-10
6040207050300
100
258
S21 PHASE CHANGE OVER DIGITAL ATTENUATOR SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)
S 21 P H A S E C H A N G E (D E G )
850
450
650
250
40
5060-10
302010050
1050
GAIN OVER ANALOG ATTENUATOR SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)G A I N (d B )
850450650250121722-18
72-3-8-13501050
GAIN vs. ANALOG ATTENUATOR SETTING
DAC CODE
G A I N (d B )
12864962241601923212
1722
-18
72-3-8-130256
Typical Operating Characteristics (continued)
(V CC = +5.0V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 8_______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V CC = +5.0V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
NOISE FIGURE vs. RF FREQUENCY
RF FREQUENCY (MHz)N O I S E F I G U R E (d B )
250
450
650
850114861097550
1050
NOISE FIGURE vs. RF FREQUENCY
RF FREQUENCY (MHz)N O I S E F I G U R E (d B )
250450650850114
8610975501050
OUTPUT P1dB vs. RF FREQUENCY
RF FREQUENCY (MHz)
O U T P U T P 1d B (d B m )
25045065085021
15
1720
191816501050
OUTPUT P1dB vs. RF FREQUENCY
RF FREQUENCY (MHz)
O U T P U T P 1d B (d B m )
250
450
650
850
211517
20191816
50
1050
OUTPUT IP3 vs. RF FREQUENCY
RF FREQUENCY (MHz)
O U T P U T I P 3 (d B m )
250
450
650
850
50
304540
35
50
1050
OUTPUT IP3 vs. RF FREQUENCY
RF FREQUENCY (MHz)
O U T P U T I P 3 (d B m )
250
450
650
850
50
3045
40
35
50
1050
OUTPUT IP3
vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)
O U T P U T I P 3 (d B m )
4
8
12
16
20
24
28
42
38
4140
39
32
OUTPUT IP3
vs. ANALOG ATTENUATOR STATE
DAC CODE
O U T P U T I P 3 (d B m )
32
64
96
12816019222445
25
4035
30
256
2nd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)
2n d H A R M O N I C (d B c )
250
450
650
850
80
4070
60
50
50
1050
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
_______________________________________________________________________________________9
2nd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)
2n d H A R M O N I C (d B c )
250
450
650
850
80
4070
60
50
50
1050
2nd HARMONIC
vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)
2n d H A R M O N I C (d B c )
4
8
12
16
20
24
28
80
60
75
70
65
32
2nd HARMONIC
vs. ANALOG ATTENUATOR STATE
DAC CODE
2n d H A R M O N I C (d B c )
32
64
9612816019222480
60
75
70
65
256
3rd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)
3r d H A R M O N I C (d B c )
250
450
650
850
110
601009080
70
50
1050
3rd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)
3r d H A R M O N I C (d B c )
250
450
650
850
110
601009080
70
50
1050
3rd HARMONIC
vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)
3r d H A R M O N I C (d B c )
48121620242832
10070
9585809075
03rd HARMONIC
vs. ANALOG ATTENUATOR STATE
DAC CODE
3r d H A R M O N I C (d B c )
32
64
96
128
160192224256
10070
95858090
750
OIP2 vs. RF FREQUENCY
RF FREQUENCY (MHz)O I P 2 (d B m )
250
450
650
850
1050
7540706055
50654550
OIP2 vs. RF FREQUENCY
RF FREQUENCY (MHz)
O I P 2 (d B m )
250
450
650
850
7540706555604550
50
1050
Typical Operating Characteristics (continued)
(V CC = +5.0V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 10______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V CC = +5.0V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
OIP2 vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)O I P 2 (d B m )
4
81220162428327540
7060555045650
OIP2 vs. ANALOG ATTENUATOR STATE
DAC CODE
O I P 2 (d B m )
326496160128192224256
7540
7060555045650
DAC VOLTAGE vs. DAC CODE
DAC CODE D A C V O L T A G E (V )
32
64
96
1601281922242563.002.52.01.51.0
0.50
DAC VOLTAGE vs. DAC CODE
DAC CODE
D A C V O L T A G
E (V )
326496160128192224256
3.00
2.52.01.51.0
0.50DAC VOLTAGE DRIFT vs. DAC CODE
DAC CODE
D A C V O L T A G
E C H A N G E (V )
32
64
96
1601281922242560.05
-0.05
0.040.01
0.020.030-0.01-0.02-0.03-0.040
DAC VOLTAGE DRIFT vs. DAC CODE
DAC CODE
D A C V O L T A G
E C H A N G E (V )
32
64
96
160
1281922242560.0100-0.0100
0.00750.0025
0.00500-0.0025-0.0050-0.00750
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
______________________________________________________________________________________11
GAIN vs. RF FREQUENCY (DIGITAL ATTENUATOR ONLY)
RF FREQUENCY (MHz)
G A I N (d B )
250
450
650
850
1050
-5-2-1
-3-4
50
GAIN vs. RF FREQUENCY (DIGITAL ATTENUATOR ONLY)
RF FREQUENCY (MHz)
G A I N (d B )
250
450
650
850
1050
-5
-2-1
-3
-4
50
GAIN vs. RF FREQUENCY (ANALOG ATTENUATOR ONLY)
RF FREQUENCY (MHz)
G A I N (d B )
250
450
650
850
1050
-5-2-1
-3-4
50
GAIN vs. RF FREQUENCY (ANALOG ATTENUATOR ONLY)
RF FREQUENCY (MHz)
G A
I N (d B )
250
450
650
850
1050
-5-2-1
-3-4
50
Typical Operating Characteristics (continued)
(V CC = +5.0V, attenuator only , maximum gain, P IN = -20dBm and T C = +25°C, unless otherwise noted.)
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 12______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V CC = +5.0V, LC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal reference used, unless otherwise noted.)
SUPPLY CURRENT vs. V CC (LOW CURRENT MODE)
V CC (V)
S U P P L Y C U R R E N T (m A )
4.857
5.000 5.125
5.250
85
5575
65
4.750
GAIN vs. RF FREQUENCY (LOW CURRENT MODE)
RF FREQUENCY (MHz)
G A I N (d B )
250
450
650
850
1050
222114
20191817
1615
50
GAIN vs. RF FREQUENCY (LOW CURRENT MODE)
RF FREQUENCY (MHz)
G A I N
(d B )
2504506508501050
22
2114
20191817
161550INPUT MATCH OVER DIGITAL ATTENUATOR
SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)I N P U T M A T C H (d B )
250
450
650
85010500-5-30
-10-15-20-25
50
OUTPUT MATCH OVER DIGITAL ATTENUATOR
SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)O U T P U T M A T C H (d B )
250450
65085010500-5-30
-10-15-20-2550INPUT MATCH vs. ANALOG ATTENUATOR
SETTING (LOW CURRENT MODE)
DAC CODE
I N P U T M A T C H (d B )
326496128160192224256
0-5-30
-10-15-20-250
OUTPUT MATCH vs. ANALOG ATTENUATOR
SETTING (LOW CURRENT MODE)
DAC CODE
O U T P U T M A T C H (d B )
32
64
96
1281601922242560-5-30
-10-15-20-25
NOISE FIGURE vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
N O I S E F I G U R E (d B )
250
450
650
850
1050
11104
987
65
50
NOISE FIGURE vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
N O I S E F I G U
R E (d B )
250
450
650
850
1050
11
10
49876
550
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
______________________________________________________________________________________13
OUTPUT P1dB vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
O U T P U T P 1d B (d B m )
250
450
650
850
1050
18
17131615
14
50
OUTPUT P1dB vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
O U T P U T P 1d B (d B m )
250
450
650
850
1050
18
17
131615
14
50
OUTPUT IP3 vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
O U T P U T I P 3 (d B m )
250
450
650
850
1050
45
402535
30
50
OUTPUT IP3 vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
O U T P U T I P 3 (d B m )
250
450
650
850
1050
45
402535
3050
OUTPUT IP3 vs. DIGITAL ATTENUATOR
STATE (LOW CURRENT MODE)
DIGITAL ATTENUATOR STATE (dB)
O U T P U T I P 3 (d B m )
4
8
12
16
20
24
28
32
45
4025
35
300
OUTPUT IP3 vs. ANALOG ATTENUATOR
STATE (LOW CURRENT MODE)
DAC CODE
O U T P U T I P 3 (d B m )
32
64
98
128160192224256
45
4025
35
30
2nd HARMONIC vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
2n d H A R M O N I C (d B c )
250
450
650
850
1050
80
4070
6050
50
2nd HARMONIC vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
2n d H A R M O N I C (d B c )
250
450
650
850
1050
80
4070
60
50
50
2nd HARMONIC vs. DIGITAL ATTENUATOR
STATE (LOW CURRENT MODE)
DIGITAL ATTENUATOR STATE (dB)
2n d H A R M O N I C (d B c )
4
8
12
20
16
24
28
32
80
60
75
70
65
Typical Operating Characteristics (continued)
(V CC = +5.0V, LC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal reference used, unless otherwise noted.)
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 14______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V CC = +5.0V, LC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal reference used, unless otherwise noted.)
2nd HARMONIC vs. ANALOG ATTENUATOR
STATE (LOW CURRENT MODE)
DAC CODE
2n d H A R M O N I C (d B c )
32
64
96
160128192224256
80
60
75
70
65
3rd HARMONIC vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
3r d H A R M O N I C (d B c )
250
450
650
850
1050
110
6010090
8070
50
OIP2 vs. RF FREQUENCY (LOW CURRENT MODE)
RF FREQUENCY (MHz)O I P 2 (d B m )
250
450
650850105075
4070656045505550
OIP2 vs. DIGITAL ATTENUATOR STATE (LOW CURRENT MODE)
DIGITAL ATTENUATOR STATE (dB)O I P 2 (d B m )
841216202428327540
706560455055
0OIP2 vs. ANALOG ATTENUATOR STATE (LOW CURRENT MODE)
DAC CODE
O I P 2 (d B m )
643296128160192224256
75
40
7065604550550
3rd HARMONIC vs. RF FREQUENCY
(LOW CURRENT MODE)
RF FREQUENCY (MHz)
3r d H A R M O N I C (d B c )
250
450
650
850
1050
110
60100
90
80
70
50
3rd HARMONIC vs. DIGITAL ATTENUATOR
STATE (LOW CURRENT MODE)
DIGITAL ATTENUATOR STATE (dB)3r d H A R M O N I C (d B c )
4
8
12
16
20
24283210070
95908575800
3rd HARMONIC vs. ANALOG ATTENUATOR
STATE (LOW CURRENT MODE)
DAC CODE 3r d H A R M O N I C (d B c )
326496128160192224256
10070
95908575
800
OIP2 vs. RF FREQUENCY (LOW CURRENT MODE)
RF FREQUENCY (MHz)
O I P 2 (d B m )
250
450
650
850
1050
75
40
7065604550
5550
MAX2065
Typical Operating Characteristics (continued)
(V CC = +3.3V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
GAIN vs. RF FREQUENCY
RF FREQUENCY (MHz)G A I N (d B )
250
450
650
850
1050
21
13
181719
201615
1450
GAIN vs. RF FREQUENCY
RF FREQUENCY (MHz)
G A I N (d B )
2504506508501050
21
13
1817192016
151450INPUT MATCH OVER DIGITAL ATTENUATOR
SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)I N P U T M A T C H (d B )
250
450
65085010500-30
-10-15-5-20-25
50
OUTPUT MATCH OVER DIGITAL ATTENUATOR
SETTING vs. RF FREQUENCY
RF FREQUENCY (MHz)O U T P U T M A T C H (d B )
200400600800
10000-30
-10-15-5-20
-250INPUT MATCH
vs. ANALOG ATTENUATOR SETTING
DAC CODE
I N P U T M A T C H (d B )
326496128160192224256
0-30
-10-15-5-20-250
OUTPUT MATCH
vs. ANALOG ATTENUATOR SETTING
DAC CODE O U T P U T M A T C H (d B )
32
64
961281601922242560-30
-10-15-5-20-25
NOISE FIGURE vs. RF FREQUENCY
RF FREQUENCY (MHz)N O I S E F I G U R E (d B )
250
450
650
850
1050
114
987106
5
50
NOISE FIGURE vs. RF FREQUENCY
RF FREQUENCY (MHz)
N O I S E F I G U R E (d B )
250450650
850
114
987106550SUPPLY CURRENT vs. V CC
V CC (V)
S U P P L Y C U R R E N T (m A )
3.15
3.30 3.45 3.60
75
4565
55
3.00
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
______________________________________________________________________________________15
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 16______________________________________________________________________________________
OUTPUT P1dB vs. RF FREQUENCY
RF FREQUENCY (MHz)O U T P U T P 1d B (d B m )
2504506508501050179
1015141316121150
OUTPUT IP3 vs. RF FREQUENCY
RF FREQUENCY (MHz)
O U T P U T I P 3 (d B m )
2504506508501050
50
20
25
4035453050
OUTPUT IP3 vs. RF FREQUENCY
RF FREQUENCY (MHz)
O U T P U T I P 3 (d B m )
250
450
650
850
1050
5020254035453050
OUTPUT IP3
vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)
O U T P U T I P 3 (d B m )
4
8
12
16
20
24
28
32
39
3834
37
3635
OUTPUT IP3
vs. ANALOG ATTENUATOR STATE
DAC CODE
O U T P U T I P 3 (d B m )
32
64
96
128160192224256
45
4025
35
30
2nd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)
2n d H A R M O N I C (d B c )
250
450
650
850
1050
80
3040
7060
5050
2nd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)
2n d H A R M O N I C (d B c )
250
450
650
850
1050
80
30
40
7060
5050
2nd HARMONIC
vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)
2n d H A R M O N I C (d B c )
4
8
12
16
20242832
70
50
65
60
55
Typical Operating Characteristics (continued)
(V CC = +3.3V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
OUTPUT P1dB vs. RF FREQUENCY
RF FREQUENCY (MHz)O U T P U T P 1d B (d B m )
250
450
650
850
105017
910
15141316121150
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
______________________________________________________________________________________17
Typical Operating Characteristics (continued)
(V CC = +3.3V, HC mode , both attenuators set for maximum gain, P IN = -20dBm, f RF = 200MHz, and T C = +25°C, internal DAC refer-ence used, unless otherwise noted.)
3rd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)3r d H A R M O N I C (d B c )
250
450
650
850105011050
1009080706050
3rd HARMONIC vs. RF FREQUENCY
RF FREQUENCY (MHz)
3r d H A R M O N I C (d B c )
250450
6508501050
110
50
10090807060
503rd HARMONIC
vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)
3r d H A R M O N I C (d B c )
4
8
12
16
20
24
28
32
90
70
85
80
75
3rd HARMONIC
vs. ANALOG ATTENUATOR STATE
DAC CODE
3r d H A R M O N I C (d B c )
32
64
96
128160192224256
11050
100908070
600
OIP2 vs. RF FREQUENCY
RF FREQUENCY (MHz)O I P 2 (d B m )
250
450
650
850
1050
70
30
6050
40
50
OIP2 vs. RF FREQUENCY
RF FREQUENCY (MHz)
O I P 2 (d B
m )
250
450
650
850
1050
70
306050
40
50
OIP2 vs. DIGITAL ATTENUATOR STATE
DIGITAL ATTENUATOR STATE (dB)
O I P 2 (d B m )
4
8
12
16
20
24
28
32
7030
60
50
40
OIP2 vs. ANALOG ATTENUATOR STATE
DAC CODE
O I P 2 (d B m )
32
64
96
12816019222425670
30
6050
40
2nd HARMONIC
vs. ANALOG ATTENUATOR STATE
DAC CODE
2n d H A R M O N I C (d B c )
32
64
96
12816019222425680
30
7060
50
40
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA 18______________________________________________________________________________________
Pin Description
MAX2065
50MHz to 1000MHz High-Linearity, Serial/
Parallel-Controlled Analog/Digital VGA
______________________________________________________________________________________
19
Detailed Description
The MAX2065 high-linearity analog/digital variable-gain amplifier is a general-purpose, high-performance amplifier designed to interface with 50Ωsystems oper-ating in the 50MHz to 1000MHz frequency range.
The MAX2065 integrates one digital attenuator and one analog attenuator to provide 62dB of total gain control,as well as a driver amplifier optimized to provide high gain, high IP3, low noise figure, and low power consump-tion. For applications that do not require high linearity, the bias current of the amplifier can be adjusted by an exter-nal resistor to further reduce power consumption.
The digital attenuator is controlled as a slave peripheral using either the SPI-compatible interface or a parallel bus with 31dB total adjustment range in 1dB steps. An added feature allows “rapid-fire” gain selection between each of the four unique steps (prepro-grammed by the user through the SPI-compatible inter-face). The 2-pin control allows the user to quickly access any one of four customized attenuation states without reprogramming the SPI bus. The analog attenu-ator is controlled using an external voltage or through the SPI-compatible interface using an on-chip DAC.Because each of the three stages has its own external RF input and RF output, this component can be config-ured to either optimize NF (amplifier configured first),OIP3 (amplifier last), or a compromise of NF and OIP3.The device’s performance features include 22dB stand-alone amplifier gain (amplifier only), 6.5dB NF at maxi-mum gain (includes attenuator insertion loss for both attenuators), and a high OIP3 level of +42dBm. Each of these features makes the MAX2065 an ideal VGA for numerous receiver and transmitter applications.
In addition, the MAX2065 operates from a single +5V supply, or a single +3.3V supply with slightly reduced performance, and has adjustable bias to trade current consumption for linearity performance.
Analog and 5-Bit Digital
Attenuator Control
The MAX2065 integrates one analog attenuator and one 5-bit digital attenuator to achieve a high level of dynamic range. The analog attenuator has a 31dB range and is controlled using an external voltage or through the 3-wire serial peripheral interface (SPI) using an on-chip 8-bit DAC. The digital attenuator has a 31dB control range, a 1dB step size, and is programmed through the 3-wire SPI. See the Applications Information section and Table 1 for attenuator programming details.The attenuators can be used for both static and dynam-ic power control.
Driver Amplifier
The MAX2065 includes a high-performance driver with a fixed gain of 22dB. The driver amplifier circuit is opti-mized for high linearity for the 50MHz to 1000MHz fre-quency range.
Applications Information
SPI Interface and Attenuator Settings
The digital attenuator is programmed through the 3-wire SPI/MICROWIRE?-compatible serial interface using 5-bit words.Twenty-eight bits of data are shifted in MSB first and is framed by CS . When CS is low, the clock is active and data is shifted on the rising edge of the clock. When CS transitions high, the data is latched and the attenuator setting changes (Figure 1). See Table 2 for details on the SPI data format.
Table 1. Control Logic
MICROWIRE is a trademark of National Semiconductor Corp.
M A X 2065
50MHz to 1000MHz High-Linearity, Serial/Parallel-Controlled Analog/Digital VGA
Figure 1. MAX2065 SPI Timing Diagram
Table 2. SPI Data Format