MAXIM MAX2644 User Manual

EVALUATION KIT

AVAILABLE

MAX2644

2.4GHz SiGe,

High IP3 Low-Noise Amplifier

________________________________________________________________ Maxim Integrated Products 1

19-1786; Rev 1; 11/03

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.

GND

V

CC

RFIN

16RFOUT

5 GND

BIAS

MAX2644

SC70-6

TOP VIEW

2

34

Pin Configuration

MAX2644

GND

BIAS

R

BIAS

1.2kΩ

RF OUTPUTRF INPUT

V

CC

V

CC

RFOUTRFIN

C1

33pF

L1

3.3nH

BIAS

Typical Operating Circuit

General Description

The MAX2644 low-cost, high third-order intercept point
(IP3) low-noise amplifier (LNA) is designed for applica­tions in 2.4GHz WLAN, ISM, and Bluetooth radio sys­tems. It features a programmable bias, allowing the
input IP3 and supply current to be optimized for specif­ic applications. The LNA provides up to +1dBm input
IP3 while maintaining a low noise figure of 2.0dB and a
typical gain of 16dB.

The MAX2644 is designed on a low-noise, advanced
silicon-germanium (SiGe) technology. It operates with a
+2.7V to +5.5V single supply and is available in an
ultra-small 6-pin SC70 package.

________________________Applications

Bluetooth

802.11 WLAN

Home RF

Satellite CD Radio

2.4GHz ISM Band Radios

2.4GHz Cordless Phones

Wireless Local Loop (WLL)

Features

♦ Low Noise Figure (2.0dB at 2450MHz)

♦ High Gain: 16dB

♦ Adjustable IP3 and Bias Current

♦ Low-Power Standby Mode

♦ On-Chip Output Matching

♦ +2.7V to +5.5V Single-Supply Operation

♦ Ultra-Small 6-Pin SC70 Package

Ordering Information

PART TEMP RANGE

MAX2644EXT-T -40°C to +85°C 6 SC70 AAG

PIN­PACKAGE

MARK

TOP

MAX2644

2.4GHz SiGe,
High IP3 Low-Noise Amplifier

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +2.7V to +5.5V, R

BIAS

= 1.2kΩ, no RF signal applied, R

FIN

and R

FOUT

are AC-coupled and terminated to 50Ω, TA= -40°C to

+85°C. Typical values are at V

CC

= +3.0V, TA= +25 °C, unless otherwise noted.) (Note 1)

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: Devices are production tested at TA= +25°C. Minimum and maximum values are guaranteed by design and characterization

over temperature and supply voltages.

Note 2: Min/Max limits are guaranteed by design and characterization.
Note 3: The part has been characterized at the specified frequency range. Operation outside this range is possible but not guaranteed.
Note 4: Excluding PC board losses (0.3dB at the input and 0.3dB at the output of the MAX2644 EV kit).
Note 5: Measured with two input tones (f

1

= 2445MHz, f2= 2455MHz) both at -30dBm per tone. Input IP3 can be improved to

+1dBm with circuit shown in Figure 2.

Note 6: Excluding PC board losses (0.3dB typical at the input of the MAX2644 EV kit).

V

CC

to GND ..............................................................-0.3V to +6V

RFIN, RFOUT to GND…......................................................±0.3V

RFIN Power (50Ω source) ................................................+5dBm

BIAS to GND ................................................................0 to +0.3V

Operating Temperature Range ...........................-40°C to +85°C

Maximum Junction Temperature .....................................+150°C

Continuous Power Dissipation (T

A

= +70°C)

6-Pin SC70 (derate 3.1mW/°C above +70°C)..............245mW

Storage Temperature.........................................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

AC ELECTRICAL CHARACTERISTICS

(MAX2644 EV kit, VCC= +3.0V, f

RFIN

= 2450MHz, P

RFIN

= -30dBm, input and output are terminated to 50Ω, R

BIAS

= 1.2kΩ,

T

A

= +25°C, unless otherwise noted.) (Note 2)

Supply Voltage 2.7 5.5 V

Operating Supply Current

Standby Supply Current R

PARAMETER CONDITIONS MIN TYP MAX UNITS

R

= 3.9kΩ 2.7

BIAS

R

= 1.2kΩ, TA = +25°C 7.0 9.7

BIAS

R

= 1.2kΩ, TA = -40°C to +85°C 11.0

BIAS

R

= 750Ω 10.2

BIAS

is unconnected, TA = +25°C, VCC = 3.3V 100 µA

BIAS

mA

Operating Frequency (Note 3) 2400 2500 MHz

Gain (Note 4) 15 17 dB

Gain Variation Over Temperature TA = -40°C to +85°C ±0.7 ±1.0 dB

Input Third-Order Intercept Point
(Note 5)

Input 1dB Compression Point -13 dBm

Noise Figure (Note 6) 2.0 2.5 dB

Input Return Loss -15 dB

Output Return Loss -10 dB

Reverse Isolation -30 dB

PARAMETER CONDITIONS MIN TYP MAX UNITS

R

= 750Ω -4

BIAS

RBIAS = 1.2kΩ

BIAS = 3.9kΩ

R

-3

-8

dBm

MAX2644

2.4GHz SiGe,

High IP3 Low-Noise Amplifier

_______________________________________________________________________________________ 3

Typical Operating Characteristics

(P

RFIN

= -30dBm, ZS= ZL= 50Ω, VCC= +3.0V, f

RFIN

= 2450MHz, R

BIAS

= 1.2kΩ, TA= +25°C, unless otherwise noted.)

0

4

2

8

6

12

10

14

2.5 3.5 4.03.0 4.5 5.0 5.5

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX2644 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

TA = +25°C

TA = -40°C

TA = +85°C

R

BIAS

= 1.2kΩ

13

15

14

17

16

18

19

0.5 2.0 2.51.0 1.5 3.0 3.5 4.0

GAIN vs. R

BIAS

MAX2644 toc05

R

BIAS

(kΩ)

GAIN (dB)

TA = -40°C

TA = +85°C

TA = +25°C

-20

-14

-16

-18

-12

-10

-8

-6

-4

-2

0

2200 24002300 2500 2600 2700

INPUT AND OUTPUT RETURN LOSS

vs. FREQUENCY

MAX2644 toc06

FREQUENCY (MHz)

REVERSE ISOLATION (dB)

OUTPUT RETURN LOSS

R

BIAS

= 1.2kΩ

INPUT RETURN LOSS

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

2350 2400 2450 2500 2550

NOISE FIGURE vs. FREQUENCY

MAX2644 toc08

FREQUENCY (MHz)

NOSIE FIGURE (dB)

R

BIAS

= 1.2kΩ

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

-40 -15 10 35 60 85

NOISE FIGURE vs. TEMPERATURE

MAX2644 toc09

TEMPERATURE (°C)

NOSIE FIGURE (dB)

R

BIAS

= 1.2kΩ

10

13

12

11

14

15

16

17

18

19

20

2200 24002300 2500 2600 2700

GAIN vs. FREQUENCY

MAX2644 toc04

FREQUENCY (MHz)

GAIN (dB)

TA = -40°C

TA = +85°C

TA = +25°C

R

BIAS

= 1.2kΩ

-50

-40

-45

-30

-35

-25

-20

2200 24002300 2500 2600 2700

REVERSE ISOLATION vs. FREQUENCY

MAX2644 toc07

FREQUENCY (MHz)

REVERSE ISOLATION (dB)

TA = +25°C

TA = +85°C

R

BIAS

= 1.2kΩ

TA = -40°C

1

5

3

9

7

11

13

0.5 2.0 2.51.0 1.5 3.0 3.5 4.0

SUPPLY CURRENT vs. R

BIAS

MAX2644 toc02

R

BIAS

(kΩ)

SUPPLY CURRENT (mA)

TA = +25°C

TA = +85°C

TA = -40°C

12

15

14

13

16

17

18

19

20

21

22

2.5 3.53.0 4.0 4.5 5.0 5.5

GAIN vs. SUPPLY VOLTAGE

MAX2644 toc03

SUPPLY VOLTAGE (V)

GAIN (dB)

TA = +25°C

R

BIAS

= 1.2kΩ

TA = +85°C

TA = -40°C

MAX2644

2.4GHz SiGe,
High IP3 Low-Noise Amplifier

4 _______________________________________________________________________________________

Pin Description

Typical Operating Characteristics (continued)

(P

RFIN

= -30dBm, ZS= ZL= 50Ω, VCC= +3.0V, f

RFIN

= 2450MHz, R

BIAS

= 1.2kΩ, TA= +25°C, unless otherwise noted.)

-20

-10

-15

0

-5

5

10

-30 -20 -15-25 -10 -5 0

OUTPUT POWER vs. INPUT POWER

MAX2644 toc10

INPUT POWER (dBm)

OUTPUT POWER (dBm)

R

BIAS

= 750Ω

R

BIAS

= 1.2kΩ

R

BIAS

= 3.9kΩ

IIP3 vs. R

BIAS

MAX2644 toc11

-9

-8

-6

-7

-3

-2

-4

-5

-1

IIP3 (dBm)

0.5 1.5 2.01.0

2.5

3.0 3.5 4.0

R

BIAS

(kΩ)

TA = +85°C

TA = +25°C

TA = -40°C

INPUT P

1dB

vs. R

BIAS

MAX2644 toc12

-19

-18

-16

-17

-13

-12

-14

-15

-11

INPUT P

1dB

(dBm)

0.5 1.5 2.01.0

2.5

3.0 3.5 4.0

R

BIAS

(kΩ)

TA = +85°C

TA = -40°C

TA = +25°C

Figure 1. High Gain Design

PIN NAME DESCRIPTION

1 BIAS

2, 5 GND Ground. For optimum performance, provide a low-inductance connection to the ground plane.

3 RFIN

4V

6 RFOUT Amplifier Output. AC-coupled internally.

CC

RFIN

SMA

GAIN: 17dB
IIP3: -3dBm

Resistor Bias Control. Connect a resistor, R

, from BIAS to ground. R

BIAS

current. The current through this pin is approximately 60mV divided by R
Information).

Amplifier Input. AC-couple to this pin with a DC blocking capacitor. External matching network is
required for optimum performance.

Supply Voltage. Bypass with a capacitor directly to ground at the supply pin. Refer to V
Bypassing section for more information.

6

RFOUTBIAS

5

GND

Length = 400mils

4

V

CC

C3

2.2pF

C2
33pF

3.3nH

1

R1

1.2kΩ

2

GND

C1

33pF

L1

3

RFIN

U1

MAX2644

sets IP3 and supply

BIAS

(see Applications

BIAS

RFOUT

SMA

GND

VCC

CC

Line

MAX2644

2.4GHz SiGe,

High IP3 Low-Noise Amplifier

_______________________________________________________________________________________ 5

Applications Information

Input Matching

Input matching is required for optimum performance.
The MAX2644 requires a simple LC matching network,
as shown in the Typical Operating Circuit. To further
reduce cost and external component count, replace the
external inductor with a microstrip transmission line.
The Typical Operating Circuit shows the recommended
input matching network for the MAX2644 at 2450MHz.
These values are optimized for best simultaneous gain,
noise figure, and return loss performance.

VCCLine Bypassing

Bypassing the VCCline is necessary for optimum
gain/linearity performance. A transmission line and two
capacitors are required, as shown in the schematics in
Figures 1 and 2. The optimum dimensions and posi­tions of the components are as follows: the output
transmission line dimension is 0.532in (length) ✕ 0.012in
(width); the distance from C2 to the IC is 0.352in; and
the distance from C3 to the IC is 0.041in. Please refer
to Figures 1 and 2 for component values.

Figure 2. High Linearity Design

Figure 3. Recommended MAX2644 Standby Configurations

RFIN

SMA

GAIN: 16dB
IIP3: +1dBm

1

R1

1.2kΩ

2

GND

C1

33pF

L1

3.3nH

BIAS BIAS

MAX2644 MAX2644

3

RFIN

U1

MAX2644

6

RFOUTBIAS

5

GND

Length = 400mils

4

V

CC

C3
15pF

L2

3.9nH

C2
33pF

RFOUT

GND

V

CC

SMA

(a) (b)

MAX2644

Standby

Standby mode is achieved by disconnecting BIAS as
shown in Figure 1. Avoid capacitance at the BIAS pin
by connecting the bias resistor from BIAS to the switch.

Layout Issues

A properly designed PC board is essential to any
RF/microwave circuit. Use controlled impedance lines
on all high-frequency inputs and outputs. Bypass with
decoupling capacitors located close to the device V

CC

pin. For long VCClines, it may be necessary to add
additional decoupling capacitors. These additional
capacitors can be located farther away from the device
package. Proper grounding of the GND pins is essen­tial. If the PC board uses a topside RF ground, connect
it directly to all GND pins. For a board where the
ground plane is not on the component layer, the best
technique is to connect the GND pins to the board with
a plated through-hole located close to the package.

2.4GHz SiGe,
High IP3 Low-Noise Amplifier

6 _______________________________________________________________________________________

Table 1. MAX2644 Typical Scattering Parameters
(R

BIAS

= 750Ω, VCC= +3.0V, TA= +25°C.)

Table 2. MAX2644 Typical Scattering Parameters
(R

BIAS

= 1.2kΩ, VCC= +3.0V, TA= +25°C.)

FREQ.

(MHz)

2200 0.3372 -79.36 5.1940 170.97 0.0414 157.19 0.2818 -73.71

2250 0.3098 -70.09 5.3156 166.79 0.0445 146.70 0.2204 -67.13

2300 0.3283 -57.20 5.4281 159.22 0.0469 130.62 0.1566 -50.26

2350 0.4005 -50.46 5.4175 150.70 0.0441 108.72 0.1480 -3.96

2400 0.4839 -50.28 5.3346 143.93 0.0349 85.67 0.2795 15.12

2450 0.5443 -56.33 5.0687 136.45 0.0233 58.80 0.4179 11.12

2500 0.5758 -60.09 4.9556 132.16 0.0113 27.74 0.5135 3.28

2550 0.5784 -63.61 4.5952 127.68 0.0041 -38.98 0.5622 -2.66

2600 0.5698 -66.56 4.2364 126.58 0.0063 -110.49 0.5986 -7.45

2650 0.5600 -68.51 4.1376 126.51 0.0103 -128.93 0.6208 -10.43

2700 0.5533 -69.86 4.0729 120.60 0.0133 -140.21 0.6425 -12.93

FREQ.

(MHz)

2200 0.3482 -67.06 5.2390 -177.33 0.0402 161.53 0.2873 -76.58

2250 0.3121 -58.60 5.3790 178.72 0.0435 151.97 0.2305 -69.42

2300 0.3051 -43.64 5.5982 173.43 0.0452 136.90 0.1735 -54.22

2350 0.3693 -30.34 5.8137 166.48 0.0427 116.57 0.1582 -16.42

2400 0.4769 -29.48 5.8063 158.29 0.0341 95.13 0.2687 6.52

2450 0.5619 -35.54 5.6624 150.06 0.0236 68.36 0.4043 5.00

2500 0.5948 -42.64 5.3015 142.37 0.0117 41.34 0.5030 -2.19

2550 0.5939 -47.58 4.7813 136.67 0.0034 -13.74 0.5602 -8.04

2600 0.5825 -50.94 4.3271 134.58 0.0056 -104.09 0.5952 -12.76

2650 0.5708 -53.14 4.1961 133.48 0.0096 -124.80 0.6215 -15.97

2700 0.5604 -54.35 4.1068 128.01 0.0125 -134.75 0.6434 -18.83

S11

MAG

S11

MAG

S11 PHASE
(DEGREES)

S11 PHASE
(DEGREES)

S21

MAG

S21

MAG

S21 PHASE
(DEGREES)

S21 PHASE
(DEGREES)

S12

MAG

S12

MAG

S12 PHASE
(DEGREES)

S12 PHASE
(DEGREES)

S22

MAG

S22

MAG

S22 PHASE
(DEGREES)

S22 PHASE

(DEGREES)

MAX2644

2.4GHz SiGe,

High IP3 Low-Noise Amplifier

_______________________________________________________________________________________ 7

Table 3. MAX2644 Typical Scattering Parameters
(R

BIAS

= 3.9kΩ, VCC= +3.0V, TA= +25°C.)

Table 4. MAX2644 Typical Noise
Parameters at V

CC

= +3.0V, TA= +25°C,

R

BIAS

= 750Ω





Table 5. MAX2644 Typical Noise
Parameters at VCC= +3.0V, TA= +25°C,
R

BIAS

= 1.2kΩ





Table 6. MAX2644 Typical Noise
Parameters at V

CC

= +3.0V, TA= +25°C,

R

BIAS

= 3.9kΩ





Chip Information

TRANSISTOR COUNT: 87

FREQUENCY

FREQ.

(MHz)

2200 0.4894 -75.32 3.7368 -173.73 0.0348 156.35 0.2729 -62.97

2250 0.4566 -72.73 3.7718 -177.51 0.0363 147.30 0.2459 -53.68

2300 0.4335 -68.17 3.8855 177.43 0.0369 132.32 0.2211 -41.12

2350 0.4343 -61.46 3.9783 171.34 0.0344 116.21 0.2177 -21.15

2400 0.4695 -57.00 4.0230 165.15 0.0272 95.31 0.2823 -2.41

2450 0.5156 -57.52 4.0087 157.68 0.0179 70.07 0.3924 1.25

2500 0.5403 -61.04 3.8380 149.58 0.0079 42.40 0.4849 -2.71

2550 0.5423 -63.93 3.5140 143.30 0.0018 -46.47 0.5476 -7.30

2600 0.5361 -66.30 3.2048 140.25 0.0055 -112.91 0.5881 -11.35

2650 0.5280 -68.08 3.1204 138.55 0.0100 -132.25 0.6170 -14.57

2700 0.5217 -69.29 3.0860 132.16 0.0121 -133.97 0.6418 -17.44

S11

MAG

S11 PHASE
(DEGREES)

S21

MAG

S21 PHASE
(DEGREES)

S12

MAG

S12 PHASE
(DEGREES)

S22

MAG

F

(MHz)

2400 1.725 0.361 66.13 24.38

2450 1.747 0.360 66.93 24.76

2500 1.769 0.358 67.72 25.14

MIN

(dB)

Γ

opt

Γ

opt

ANGLE

R
(Ω)

N

FREQUENCY

(MHz)

2400 1.570 0.409 69.84 21.77

2450 1.589 0.408 70.63 21.94

2500 1.609 0.406 71.63 22.42

F

MIN

(dB)

Γ

Γ

opt

opt

ANGLE

S22 PHASE

(DEGREES)

R

N

(Ω)

FREQUENCY

(MHz)

2400 1.497 0.510 86.55 20.58

2450 1.517 0.507 86.50 20.90

2500 1.538 0.504 88.18 21.25

F
(dB)

MIN

Γ

opt

Γ

opt

ANGLE

R
(Ω)

N

MAX2644

2.4GHz SiGe,
High IP3 Low-Noise Amplifier

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Package Information (continued)

(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

.)

SC70, 6L.EPS