MAXIM MAX2691 Technical data

EVALUATION KIT AVAILABLE

19-6158; Rev 0; 12/11

MAX2691

L2 Band GPS Low-Noise Amplifier

General Description

The MAX2691 low-noise amplifier (LNA) is designed for GPS L2 applications. Designed in Maxim’s advanced SiGe process, the device achieves high gain and low noise figure while maximizing the input-referred 1dB compression point and the 3rd-order intercept point. The MAX2691 provides a high gain of 17.5dB and sub 1dB noise figure.

The device operates from a +1.6V to +3.6V single supply. The optional shutdown feature in the device reduces the typical supply current to 4FA. The device is available in a very small, lead-free, RoHS-compliant, 0.86mm x

0.86mm x 0.65mm wafer-level package (WLP).

Applications

Precision Navigation

Telematics (Asset Tracking and Management)

Avionics

Features

S High-Power Gain: 17.5dB

S Low-Noise Figure: 0.93dB

S Integrated 50Ω Output Matching Circuit

S Low Supply Current: 4.3mA

S Wide Supply Voltage Range: 1.6V to 3.6V

S Low Bill of Materials: One Inductor, Two

Capacitors

S Small Footprint: 0.86mm x 0.86mm

S Thin Profile: 0.65mm

S 0.4mm-Pitch Wafer-Level Package (WLP)

Ordering Information appears at end of data sheet.

For related parts and recommended products to use with this part, refer to www.maxim-ic.com/MAX2691.related.

Typical Application Circuit

V

CC

C1

RF

INPUT

�� Maxim Integrated Products 1

CC

C2

L1

RFIN

MAX2691

A1 A2

B1 B2

MAX2691

L1 = 8.2nH C1 = 100nF C2 = 10pF

RFOUT

OPTIONAL SHUTDOWN

GND

R1 25kI

RF OUTPUT

SHDN

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

MAX2691

L2 Band GPS Low-Noise Amplifier

ABSOLUTE MAXIMUM RATINGS

VCC to GND .......................................................... -0.3V to +3.6V

Other Pins to GND

(except RFIN) ...................-0.3V to (+ Operating VCC + 0.3V)

Maximum Current into RF Input .........................................10mA

Maximum RF Input Power ............................................... +5dBm

Continuous Power Dissipation (TA = +70°C)

4-Bump WLP (derates 9.7mW/°C above +70°C) ........776mW

Note 1: Refer to Application Note 1891: Wafer-Level Packaging (WLP) and Its Applications.

CAUTION! ESD SENSITIVE DEVICE

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

(MAX2691 EV kit, VCC = 1.6V to 3.6V, TA = -40°C to +85°C, no RF signals are applied. Typical values are at VCC = 2.85V and TA = +25°C, unless otherwise noted.) (Note 2)

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

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

Storage Temperature Range ............................ -65°C to +160°C

Lead Temperature (soldering, 10s) ........Reflow Profile (Note 1)

Soldering Temperature (reflow) ......................................+260°C

PARAMETER CONDITIONS MIN TYP MAX UNITS

Supply Voltage 1.6 2.85 3.6 V

Supply Current

Digital Input Logic-High (Note 3) 1.2 V Digital Input Logic-Low (Note 3) 0.45 V

SHDN = high Shutdown mode, SHDN = low

4.3 mA

4.0 20 µA

AC ELECTRICAL CHARACTERISTICS

(MAX2691 EV kit, VCC = 1.6V to 3.6V, TA = -40°C to +85°C, f unless otherwise noted.) (Note 2)

PARAMETER CONDITIONS MIN TYP MAX UNITS

RF Frequency L2 band 1227 MHz

Power Gain (Note 4)

Noise Figure VCC = 1.6V to 3.3V 0.93 dB

In-Band 3rd-Order Input Intercept Point

Input 1dB Compression Point (Note 6) -8.5 dBm

Input Return Loss 10.9 dB

VCC = 2.85V 13.3 17.5

VCC = 1.6V 13.1 17.4

(Note 5) -3.0 dBm

= 1227MHz. Typical values are at VCC = 2.85V and TA = +25°C,

RFIN

dB

�� Maxim Integrated Products 2

MAX2691

L2 Band GPS Low-Noise Amplifier

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2691 EV kit, VCC = 1.6V to 3.6V, TA = -40°C to +85°C, f unless otherwise noted.) (Note 2)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Return Loss 15.6 dB

Reverse Isolation 45 dB

Note 2: Min and max limits guaranteed by test at TA = +25°C and guaranteed by design and characterization at TA = -40°C and

TA = +85°C, unless otherwise noted.

Note 3: Min and max limits guaranteed by test at TA = +25°C. Note 4: Min limit guaranteed by design and characterization. Note 5: Measured with the two tones located at 1MHz and 2MHz offset from the center of the GPS band with -30dBm/tone. Note 6: Measured with a tone located at 5MHz offset from the center of the GPS band.

= 1227MHz. Typical values are at VCC = 2.85V and TA = +25°C,

RFIN

Typical Operating Characteristics

(MAX2691 EV kit. Typical values are at VCC = 2.85V, TA = +25°C, and f

INPUT RETURN LOSS vs. FREQUENCY

0

-5

-10

-15

-20

(dB)

|

S11

-25

|

-30

-35

-40

-45 500 2500

FREQUENCY (MHz)

200015001000

MAX2691 toc01

20

15

10

5

GAIN (dB)

0

-5

-10 500 2500

GAIN vs. FREQUENCY

FREQUENCY (MHz)

= 1227MHz, unless otherwise noted.)

RFIN

REVERSE ISOLATION vs. FREQUENCY

0

-10

MAX2691 toc02

-20

-30

-40

(dB)

|

S12

-50

|

-60

-70

-80

200015001000

-90 500 2500

MAX2691 toc03

200015001000

FREQUENCY (MHz)

�� Maxim Integrated Products 3

MAX2691

L2 Band GPS Low-Noise Amplifier

Typical Operating Characteristics (continued)

(MAX2691 EV kit. Typical values are at VCC = 2.85V, TA = +25°C, and f

OUTPUT RETURN LOSS vs. FREQUENCY

0

-5

-10

(dB)

|

S22

|

-15

-20

-25 500 2500

FREQUENCY (MHz)

200015001000

MAX2691 toc04

INPUT P1dB COMPRESSION vs.

SUPPLY VOLTAGE AND TEMPERATURE

-6

-8

-10

-12

INPUT P1dB (dBm)

-14

TA = -40°C

T

= +85°C

A

T

A

MAX2691 toc06

= +25°C

= 1227MHz, unless otherwise noted.)

RFIN

INBAND IIP3 vs. SUPPLY VOLTAGE

AND TEMPERATURE

2

TWO TONES LOCATED AT +1MHz AND +2MHz FROM 1227MHz. P

1

0

-1

IIP3 (dBm)

-2

-3

-4

1.6 3.6

= -30dBm/TONE

IN

TA = -40°C

TA = +25°C

SUPPLY VOLTAGE (V)

1dB GAIN DESENSE vs.

BLOCKER FREQUENCY

5

0

-5

(dBm)

-10

-15

BLOCKER POWER

-20

MAX2691 toc05

TA = +85°C

3.12.62.1

MAX2691 toc07

-16

1.6 3.6

SUPPLY VOLTAGE (V)

3.12.62.1

-25 500 2500

BLOCKER FREQUENCY (MHz)

200015001000

�� Maxim Integrated Products 4

L2 Band GPS Low-Noise Amplifier

Bump Configuration

TOP VIEW

+

V

A1 A2

CC

MAX2691

B1 B2

RFIN

WLP

BUMP NAME FUNCTION

A1 V

A2

B1 RFIN RF Input. Requires a DC-blocking capacitor and external matching components. B2 GND Ground. Connect to the PCB ground plane.

CC

RFOUT

(SHDN)

Supply Voltage. Bypass to ground with a 10pF capacitor as close as possible to the IC.

RF Output/SHDN Input. RFOUT is internally matched to 50I and pulled up to VCC through a 1MI resistor. SHDN is shared with the RFOUT bump. The device is in active mode by default once VCC is applied. RFOUT(SHDN) can be pulled to a DC low through a 25kI resistor to shut down the IC.

RFOUT (SHDN)

GND

Bump Description

MAX2691

Detailed Description

The MAX2691 LNA is designed for GPS L2 applications. The device features a power-shutdown control mode to eliminate the need for an external supply switch. The device achieves high gain, low noise figure, and excellent linearity.

Input and Output Matching

The MAX2691 requires an off-chip input match. Only an inductor in series with a DC-blocking capacitor is needed to form the input matching circuit. The Typical Application

Circuit shows the recommended input-matching network.

These values are optimized for the best simultaneous gain, noise figure, and return loss performance. Reducing the input coupling capacitor results in a lower IIP3. The device integrates an on-chip output matching to 50I at the output, eliminating the need for external matching components. Table 1 lists typical device S parameters and Kf values. Typical noise parameters are shown in Table 2.

Shutdown

The MAX2691 includes an optional shutdown feature to turn off the entire chip. The device is placed in active

mode by default once VCC is applied, due to the on-chip pullup resistor to VCC at the RFOUT bump (shared with the SHDN input). To shut down the part, apply a logic-low to the RFOUT bump through an external resistor with an adequate value, e.g., 25kI, in order not to load the RF output signal during active operation.

Applications Information

A properly designed PCB is essential to any RF microwave circuit. Use controlled-impedance lines on all high-frequency inputs and outputs. Bypass VCC with decoupling capacitors located close to the device. For long VCC lines, it may be necessary to add decoupling capacitors. Locate these additional capacitors further away from the device package. Proper grounding of the GND pin is essential. If the PCB uses a topside RF ground, connect it directly to the GND pin. For a board where the ground is not on the component layer, connect the GND pin to the board with multiple vias close to the package.

Refer to www.maxim-ic.com for the MAX2691 EV kit schematic, Gerber data, PADS layout file, and BOM information.

�� Maxim Integrated Products 5

L2 Band GPS Low-Noise Amplifier

Table 1. Typical S Parameter Values and K-Factor

MAX2691

FREQ.

(MHz)

700 -2.1 -78.1 3.5 -175.7 -54.0 113.3 -1.3 -124.9 16.75126 800 -2.5 -87.1 6.0 175.7 -47.7 112.0 -1.6 -143.3 8.847551

900 -2.8 -96.2 8.8 163.0 -55.5 85.4 -2.4 -162.8 22.33037 1000 -3.1 -104.3 11.7 146.2 -53.8 54.0 -3.9 175.0 19.54059 1100 -3.4 -112.3 14.4 119.2 -46.3 33.8 -8.3 149.5 9.366309 1200 -3.7 -119.4 16.0 83.5 -46.9 15.3 -19.1 -126.9 9.788318 1220 -3.7 -120.7 16.1 75.6 -47.6 -1.0 -14.2 -114.7 10.25069 1240 -3.7 -122.4 16.0 67.9 -49.4 20.3 -10.9 -114.4 12.09861 1260 -3.8 -123.7 15.9 60.1 -49.7 14.9 -8.7 -118.5 12.1323 1280 -3.8 -125.0 15.6 52.8 -47.3 -6.0 -6.9 -124.3 8.793041 1300 -3.8 -126.6 15.2 46.0 -43.5 19.6 -5.7 -130.2 5.277003 1400 -4.0 -133.5 13.4 18.4 -44.9 -22.8 -2.6 -157.6 4.94144 1500 -4.1 -140.3 11.3 -0.5 -48.5 -21.4 -1.6 -179.3 6.656188 1600 -4.1 -147.6 9.4 -15.6 -47.7 -23.6 -1.3 163.8 5.983826 1700 -4.1 -154.6 7.8 -28.5 -44.8 -16.5 -1.0 148.8 4.18904

S11 MAG

(dB)

S11

PHASE

(DEGREES)

S21 MAG

(dB)

S21

PHASE

(DEGREES)

S12 MAG

(dB)

S12

PHASE

(DEGREES)

S22 MAG

(dB)

S22

PHASE

(DEGREES)

Table 2. Typical Noise Parameters (VCC = 2.85V, TA = +25NC)

FREQUENCY (MHz) FMIN (dB)

1200 0.66 0.45 47 8.37 1210 0.66 0.45 48 8.35 1220 0.66 0.45 48 8.33 1230 0.66 0.45 48 8.30 1240 0.66 0.45 49 8.28 1250 0.66 0.45 49 8.26 1260 0.66 0.45 50 8.24 1270 0.67 0.45 50 8.22 1280 0.67 0.44 50 8.20 1290 0.67 0.44 51 8.18 1300 0.67 0.44 51 8.17

|G

| |G

OPT

| ANGLE

RN (I)

K

f

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX2691EWS+T

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

-40NC to +85NC

4 WLP

Chip Information

PROCESS: SiGe BiCMOS

�� Maxim Integrated Products 6

Package Information

For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.

PACKAGE

TYPE

4 WLP W40A0+1

PACKAGE

CODE

OUTLINE

NO.

21-0480

LAND

PATTERN NO.

Refer to Application

Note 1891

MAX2691

L2 Band GPS Low-Noise Amplifier

Revision History

REVISION

NUMBER

0 12/11 Initial release —

REVISION

DATE

DESCRIPTION

PAGES

CHANGED

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. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 7

©

2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.

MAXIM MAX2691 Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual

General Description

Applications

Features

Typical Application Circuit

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

AC ELECTRICAL CHARACTERISTICS

Typical Operating Characteristics

Bump Configuration

Bump Description

Detailed Description

Input and Output Matching

Shutdown

Applications Information

Table 1. Typical S Parameter Values and K-Factor

Ordering Information

Chip Information

Package Information

Revision History