MAXIM MAX12000 Technical data

General Description

The MAX12000 GPS front-end amplifier IC is designed
for automotive and marine GPS satellite navigation
antenna modules or for any application that needs to
compensate for cable losses from the GPS antenna to
receiver. Two unconditionally stable low-noise amplifier
stages provide the high gain and integrated I/O match­ing to minimize the need for external matching compo­nents and eliminate the need for additional gain stages.
The MAX12000 features the option to place a bandpass
ceramic or SAW filter between the two amplifier stages
to provide a narrow-band output to further improve the
noise performance of the GPS receiver. Additionally, a

3.4dB gain step is provided to compensate for cable
loss variation between different applications.

The MAX12000 is designed to operate at the GPS fre­quency of 1575MHz with a 34.8dB typical cascaded
gain and a 25mA supply current. The two LNA stages
allow the use of a wide range of GPS filter types for
maximum flexibility in system design. The final RF out­put pin, which drives the cable to the GPS receiver, is
also the power-supply connection that accepts a DC
supply in the +3.0V to +5.5V range. Alternatively, the
DC supply can be applied to pin 4.

The GPS front-end amplifier is designed on a low-noise,
advanced SiGe process and is available in a lead-free,
10-pin TDFN surface-mount package (3mm x 3mm).

Applications

Integrated Automotive and Marine GPS
Receivers

Features

♦ First Amp Noise Figure*: 1.0dB

♦ High Gain**: 34.8dB

♦ 3.4dB Gain Step

♦ Integrated 50Ω Output Matching

♦ 3.0V to 5.5V Supply Voltage Range

♦ Small, Low-Cost Package (3mm x 3mm)

♦ ESD Protected to ±1kV Human Body Model

MAX12000

1575MHz GPS Front-End Amplifier

________________________________________________________________ Maxim Integrated Products 1

1

+

3

4

10

8

7

RFOUT1

DC

GENERATION

GND

GAIN_SELECT

RFIN2

GND

EXTCAP/ALT_V

CC

MAX12000

29

GNDGND

56

RFIN1RFOUT2/V

CC

TDFN

TOP VIEW

AMP 2

AMP 1

Pin Configuration/Functional Diagram

Ordering Information

19-4021; Rev 0; 3/06

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.

+Denotes lead-free package.

Typical Operating Circuit appears at end of data sheet.

*Without external input impedance match.
**First amplifier input is impedance matched (S11= -10dB).

Second amplifier set to high gain. Amplifiers cascaded without
interstage filter.

EVALUATION KIT

AVAILABLE

PART

TEMP RANGE

PIN-

PKG
CODE

10 TDFN

T1033-2

PACKAGE

MAX12000ETB+ -40°C to +85°C

MAX12000

1575MHz GPS Front-End Amplifier

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +3.0V to +5.5V, TA= -40°C to +85°C. Typical values are at +5.0V and at TA= +25°C. Pin 7 open, 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.

RFOUT1, RFOUT2, EXTCAP to GND...........-0.3V to (VCC+ 0.5V)

RFIN1 Input Power (50Ω source) ...................................+15dBm

RFIN1 to GND........................................................-0.3V to +0.3V

RFIN2 to GND........................................................-0.3V to +1.0V

GAIN_SELECT to GND...............................-0.3V to (V

CC

+ 0.3V)

Continuous Power Dissipation (T

A

= +70°C)

10-Pin TDFN (derate 18.5mW/°C above +70°C) ........1481mW

Operating Ambient Temperature Range ...........-40°C to +105°C

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

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

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

CAUTION! ESD SENSITIVE DEVICE

PARAMETER

CONDITIONS

UNITS

Supply Voltage V

CC

3.0 5.5 V

TA = +25°C

25

Supply Current I

CC

TA = -40°C to 105°C (Note 2) 33

mA

Gain-Select Input Current I

IL

VIL = 0V 20 100 µA

AC ELECTRICAL CHARACTERISTICS

(VCC= +3.0V to +5.5V, PIN= -40dBm, fIN= 1575MHz, TA= -40°C to +85°C. Typical values are at +5.0V and at TA= +25°C. Input
matched to 50Ω, load = 50Ω, pin 7 open, unless otherwise noted.) (Note 1)

PARAMETER

CONDITIONS

UNITS

Operation Frequency f

RF

MHz

50Ω source with no input match (Note 3)

AMP 1 Gain ⏐S21⏐

50Ω source with input match

dB

AMP 1 Gain Variation Over
Temperature

0.3 dB

AMP 1 Noise Figure NF No input match (Notes 3, 4) 1 1.3 dB

AMP 1 Input Third-Order
Intercept Point

IIP3

Two tones at 1574.5MHz and 1575.5MHz,

-35dBm per tone

-12

dBm

AMP 1 Input 1dB Compression
Point

50Ω source with no input match (Note 3) -19

dBm

AMP 1 Input Return Loss ⏐S11⏐ No input match (Note 3)

dB

AMP 1 Output Return Loss ⏐S22⏐

dB

AMP 1 Reverse Isolation ⏐S12⏐ -33 dB
AMP 2 Gain ⏐S21⏐

17

dB

AMP 2 Gain Step

dB

AMP 2 Gain Variation Over
Temperature

1dB

AMP 2 Noise Figure NF (Note 4) 2.0 2.4 dB

AMP 2 Output Third-Order
Intercept Point

OIP3

Two tones at 1574.5MHz and 1575.5MHz,

-30dBm per tone

dBm

AMP 2 Output 1dB Compression
Point

1.5 5.3

dBm

SYMBOL

MIN TYP MAX

15.0

SYMBOL

Gain change when pin 7 is shorted to GND -2.8 -3.4 -4.0

MIN TYP MAX

1575

15.0 16.7 18.5

17.8

15.0

-4.4

-14.5

16.0

30.2

19.6

MAX12000

1575MHz GPS Front-End Amplifier

_______________________________________________________________________________________ 3

0.6

0.8

0.7

1.0

0.9

1.1

1.2

1.3

1.4

-40 0 20-20 406080100

AMP 1 NOISE FIGURE vs. TEMPERATURE

(WITHOUT EXTERNAL INPUT IMPEDANCE MATCH)

MAX12000 toc01

TEMPERATURE (°C)

NOISE FIGURE (dB)

1.0

2.0

1.5

3.0

2.5

3.5

4.0

4.5

5.5

5.0

-40 0 20-20 40 60 80 100

AMP 2 NOISE FIGURE vs. TEMPERATURE

MAX12000 toc02

TEMPERATURE (°C)

NOISE FIGURE (dB)

LOW-GAIN MODE

HIGH-GAIN MODE

22.5

21.5

24.5

23.5

26.5

25.5

27.5

3.0 4.03.5 4.5 5.0 5.5

SUPPLY VOLTAGE vs. CURRENT

(PIN 7 OPEN)

MAX12000 toc03

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

TA = +105°C

TA = +85°C

TA = +25°C

TA = -40°C

17.4

17.3

17.6

17.5

17.8

17.7

17.9

18.0

18.1

3.0 4.03.5 4.5 5.0 5.5

AMP 1 GAIN vs. SUPPLY VOLTAGE

(WITH EXTERNAL INPUT IMPEDANCE MATCH)

MAX12000 toc04

SUPPLY VOLTAGE (V)

GAIN (dB)

TA = +105°C

TA = +85°C

TA = +25°C

TA = -40°C

16.0

15.5

17.0

16.5

18.0

17.5

3.0 4.03.5 4.5 5.0 5.5

AMP 2 GAIN vs. SUPPLY VOLTAGE

(PIN 7 OPEN)

MAX12000 toc05

SUPPLY VOLTAGE (V)

GAIN (dB)

TA = +105°C

TA = +85°C

TA = +25°C

TA = -40°C

13.0

12.5

12.0

14.0

13.5

15.0

14.5

3.0 4.03.5 4.5 5.0 5.5

AMP 2 GAIN vs. SUPPLY VOLTAGE

(PIN 7 SHORT TO GND)

MAX12000 toc06

SUPPLY VOLTAGE (V)

GAIN (dB)

TA = +105°C

TA = +85°C

TA = +25°C

TA = -40°C

Typical Operating Characteristics

(PIN= -40dBm, fIN= 1575MHz, inputs and outputs are terminated to 50Ω, VCC= +5.0V, TA= +25°C, unless otherwise noted.)

Note 1: At T

A

= -40°C, the minimum and maximum values are guaranteed by design and characterization, unless otherwise noted.

Note 2: At T

A

= -40°C and +105°C, the maximum value is guaranteed by design and characterization.

Note 3: Measured using MAX12000 evaluation board with a DC-blocking capacitor at the input of LNA 1.
Note 4: At T

A

= +25°C, the maximum value is guaranteed by design and characterization. Specification is corrected for board

losses on the MAX12000 EV kit.

AC ELECTRICAL CHARACTERISTICS (continued)

(VCC= +3.0V to +5.5V, PIN= -40dBm, fIN= 1575MHz, TA= -40°C to +85°C. Typical values are at +5.0V and at TA= +25°C. Input
matched to 50Ω, load = 50Ω, pin 7 open, unless otherwise noted.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

AMP 2 Input Return Loss ⏐S11⏐ -21 dB
AMP 2 Output Return Loss ⏐S22⏐

dB

AMP 2 Reverse Isolation ⏐S12⏐ -25 dB

-8.8