EVALUATION KIT AVAILABLE
MAX12000
1575MHz GPS Front-End Amplifier
General Description
The MAX12000 GPS front-end amplifier IC is designed
for marine GPS satellite navigation antenna modules or
for any application that needs to compensate for cable
losses from the GPS antenna to receiver. Two uncondi-
tionally 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 fre-
quency 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 pow-
er-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).
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
*Without external input impedance match.
**First amplifier input is impedance matched (S
11
= -10dB).
Second amplifier set to high gain. Amplifiers cascaded without
interstage filter.
Ordering Information
PART
MAX12000ETB+
TEMP RANGE
-40°C to +85°C
PIN-
PACKAGE
10 TDFN
+Denotes a lead(Pb)-free/RoHS-compliant package.
Applications
Typical Operating Circuit appears at end of data sheet.
●
Marine GPS Receivers
Pin Configuration/Functional Diagram
TOP VIEW
+
RFIN2
GND
GND
EXTCAP/ALT_V
CC
RFOUT2/V
CC
1
2
3
4
5
DC
GENERATION
AMP 2
AMP 1
MAX12000
10 RFOUT1
9
8
7
6
GND
GND
GAIN_SELECT
RFIN1
TDFN
19-4021; Rev 1; 9/14
MAX12000
1575MHz GPS Front-End Amplifier
Absolute Maximum Ratings
RFOUT1, RFOUT2, EXTCAP to GND ..... -0.3V to (V
CC
+ 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
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.
CAUTION!
ESD SENSITIVE DEVICE
DC Electrical Characteristics
(V
CC
= +3.0V to +5.5V, T
A
= -40°C to +85°C. Typical values are at +5.0V and at T
A
= +25°C. Pin 7 open, unless otherwise noted.)
(Note 1)
PARAMETER
Supply Voltage
Supply Current
Gain-Select Input Current
SYMBOL
V
CC
I
CC
I
IL
T
A
= +25°C
V
IL
= 0V
CONDITIONS
MIN
3.0
15.0
25
20
T
A
= -40°C to 105°C (Note 2)
TYP
MAX
5.5
30.2
33
100
UNITS
V
mA
µA
AC Electrical Characteristics
PARAMETER
Operation Frequency
AMP 1 Gain
AMP 1 Gain Variation Over
Temperature
AMP 1 Noise Figure
AMP 1 Input Third-Order
Intercept Point
AMP 1 Input 1dB Compression
Point
AMP 1 Input Return Loss
AMP 1 Output Return Loss
AMP 1 Reverse Isolation
AMP 2 Gain
AMP 2 Gain Step
AMP 2 Gain Variation Over
Temperature
AMP 2 Noise Figure
AMP 2 Output Third-Order
Intercept Point
AMP 2 Output 1dB Compression
Point
NF
OIP3
NF
IIP3
(V
CC
= +3.0V to +5.5V, P
IN
= -40dBm, f
IN
= 1575MHz, T
A
= -40°C to +85°C. Typical values are at +5.0V and at T
A
= +25°C. Input
matched to 50Ω, load = 50Ω, pin 7 open, unless otherwise noted.) (Note 1)
SYMBOL
f
RF
|S
21
|
CONDITIONS
50Ω source with no input match (Note 3)
50Ω source with input match
MIN
15.0
TYP
1575
16.7
17.8
0.3
No input match (Notes 3, 4)
Two tones at 1574.5MHz and 1575.5MHz,
-35dBm per tone
50Ω source with no input match (Note 3)
|S
11
|
|S
22
|
|S
12
|
|S
21
|
Gain change when pin 7 is shorted to GND
15.0
-2.8
No input match (Note 3)
1
-12
-19
-4.4
-14.5
-33
17
-3.4
1
(Note 4)
Two tones at 1574.5MHz and 1575.5MHz,
-30dBm per tone
1.5
2.0
16.0
5.3
2.4
19.6
-4.0
1.3
18.5
MAX
UNITS
MHz
dB
dB
dB
dBm
dBm
dB
dB
dB
dB
dB
dB
dB
dBm
dBm
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MAX12000
1575MHz GPS Front-End Amplifier
AC Electrical Characteristics (continued)
(V
CC
= +3.0V to +5.5V, P
IN
= -40dBm, f
IN
= 1575MHz, T
A
= -40°C to +85°C. Typical values are at +5.0V and at T
A
= +25°C. Input
matched to 50Ω, load = 50Ω, pin 7 open, unless otherwise noted.) (Note 1)
PARAMETER
AMP 2 Input Return Loss
AMP 2 Output Return Loss
AMP 2 Reverse Isolation
Note
Note
Note
Note
1:
2:
3:
4:
SYMBOL
|S
11
|
|S
22
|
|S
12
|
CONDITIONS
MIN
TYP
-21
-8.8
-25
MAX
UNITS
dB
dB
dB
At T
A
= -40°C, the minimum and maximum values are guaranteed by design and characterization, unless otherwise noted.
At T
A
= -40°C and +105°C, the maximum value is guaranteed by design and characterization.
Measured using MAX12000 evaluation board with a DC-blocking capacitor at the input of LNA 1.
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.
Typical Operating Characteristics
AMP 1 NOISE FIGURE vs. TEMPERATURE
(WITHOUT EXTERNAL INPUT IMPEDANCE MATCH)
MAX12000 toc01
(P
IN
= -40dBm, f
IN
= 1575MHz, inputs and outputs are terminated to 50Ω, V
CC
= +5.0V, T
A
= +25°C, unless otherwise noted.)
SUPPLY VOLTAGE vs. CURRENT
(PIN 7 OPEN)
27.5
SUPPLY CURRENT (mA)
26.5
25.5
24.5
23.5
22.5
21.5
T
A
= -40°C
3.0
3.5
4.0
4.5
5.0
5.5
T
A
= +85°C
T
A
= +105°C
MAX12000 toc03
1.3
NOISE FIGURE (dB)
1.2
1.1
1.0
0.9
0.8
0.7
0.6
-40
-20
0
20
40
60
80
100
5.0
4.5
NOISE FIGURE (dB)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
-40
-20
0
20
40
60
80
100
HIGH-GAIN MODE
LOW-GAIN MODE
MAX12000 toc02
1.4
5.5
AMP 2 NOISE FIGURE vs. TEMPERATURE
T
A
= +25°C
TEMPERATURE (°C)
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
MAX12000 toc04
18.0
17.9
GAIN (dB)
17.8
17.7
17.6
17.5
17.4
17.3
3.0
3.5
4.0
4.5
MAX12000 toc05
T
A
= -40°C
T
A
= +25°C
17.5
17.0
16.5
16.0
15.5
T
A
= -40°C
14.5
14.0
GAIN (dB)
13.5
13.0
12.5
12.0
T
A
= -40°C
T
A
= +25°C
T
A
= +85°C
T
A
= +105°C
3.0
3.5
4.0
4.5
5.0
GAIN (dB)
T
A
= +25°C
T
A
= +85°C
T
A
= +105°C
T
A
= +85°C
T
A
= +105°C
5.0
5.5
3.0
3.5
4.0
4.5
5.0
5.5
5.5
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
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MAX12000 toc06
18.1
AMP 1 GAIN vs. SUPPLY VOLTAGE
(WITH EXTERNAL INPUT IMPEDANCE MATCH)
18.0
AMP 2 GAIN vs. SUPPLY VOLTAGE
(PIN 7 OPEN)
15.0
AMP 2 GAIN vs. SUPPLY VOLTAGE
(PIN 7 SHORT TO GND)
MAX12000
1575MHz GPS Front-End Amplifier
Typical Operating Characteristics (continued)
(P
IN
= -40dBm, f
IN
= 1575MHz, inputs and outputs are terminated to 50Ω, V
CC
= +5.0V, T
A
= +25°C, unless otherwise noted.)
AMP 1 GAIN vs. FREQUENCY
(WITH EXTERNAL INPUT IMPEDANCE MATCH)
MAX12000 toc07
MAX12000 toc08
19
18
GAIN (dB)
17
16
15
14
13
12
800
1000
1200
1400
1600
1800
16
14
12
GAIN (dB)
10
8
6
4
2
LOW-GAIN MODE
HIGH-GAIN MODE
-17
INPUT P
1dB
(dBm)
-18
-19
-20
-21
-22
2000
0
800
1000
1200
1400
1600
1800
2000
-40
-20
0
20
40
60
80
100
FREQUENCY (MHz)
FREQUENCY (MHz)
TEMPERATURE (°C)
MAX12000 toc10
MAX12000 toc11
5.6
OUTPUT P
1dB
(dB)
5.4
5.2
5.0
4.8
-2.5
-3.0
S11 (dB)
-3.5
-4.0
-4.5
-5.0
-6
-8
S22 (dB)
-10
-12
-14
-16
-40
-20
0
20
40
60
80
100
800
1000
1200
1400
1600
1800
2000
800
1000
1200
1400
1600
1800
2000
TEMPERATURE (°C)
FREQUENCY (MHz)
FREQUENCY (MHz)
AMP 2 S11
MAX12000 toc13
AMP 2 S22
-6
-8
-10
S22 (dB)
-12
-14
-16
-18
-20
MAX12000 toc14
0
-5
-10
-15
-20
-25
800
-4
S11 (dB)
1000
1200
1400
1600
1800
2000
-22
800
1000
1200
1400
1600
1800
2000
FREQUENCY (MHz)
FREQUENCY (MHz)
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MAX12000 toc12
5.8
AMP 2 OUTPUT P
1dB
vs. TEMPERATURE
(PIN 7 OPEN)
AMP 1 S11
(WITHOUT EXTERNAL INPUT IMPEDANCE MATCH)
-2.0
-4
AMP 1 S22
MAX12000 toc09
20
18
AMP 2 GAIN vs. FREQUENCY
AMP 1 INPUT P
1dB
vs. TEMPERATURE
(WITHOUT EXTERNAL INPUT IMPEDANCE MATCH)
-16
MAX12000
1575MHz GPS Front-End Amplifier
Typical Operating Characteristics (continued)
(P
IN
= -40dBm, f
IN
= 1575MHz, inputs and outputs are terminated to 50Ω, V
CC
= +5.0V, T
A
= +25°C, unless otherwise noted.)
AMP 1 S12
MAX12000 toc15
AMP 2 S12
MAX12000 toc16
-32
-20
-24
-28
-32
-36
-40
800
-34
S12 (dB)
-36
-38
-40
800
1000
1200
1400
1600
1800
2000
S12 (dB)
1000
1200
1400
1600
1800
2000
FREQUENCY (MHz)
FREQUENCY (MHz)
Pin Description
PIN
1
2, 3, 8, 9
4
5
6
7
10
EP
NAME
RFIN2
GND
EXTCAP/
ALT_V
CC
RFOUT2/V
CC
RFIN1
FUNCTION
Amplifier 2 Input. Incorporates an internal DC-blocking capacitor and is internally matched to 50Ω.
This input is designed to be connected to a bandpass filter.
Electrical Ground
External Smoothing Capacitor for Internal Supply Voltage or Can Be Used as the External DC Supply
Pin to Eliminate the Need for a Bias-T on Pin 5
Amplifier 2 Output. Incorporates an internal DC-blocking capacitor and is internally matched to 50Ω.
DC bias on this pin serves as the power supply through a bias-T.
Amplifier 1 Input. Requires external DC-blocking capacitor and matching components.
Amplifier 1 Output. Incorporates an internal DC-blocking capacitor and is internally matched to 50Ω.
This output is designed to drive a bandpass filter.
Ground. The exposed pad must be soldered to the circuit board for proper thermal and electrical
performance.
GAIN_SELECT AMP 2 Gain Select. Open is high-gain mode. Short to ground is low-gain mode.
RFOUT1
Exposed Pad
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