19-4383; Rev 1; 3/09
KIT
ATION
EVALU
BLE
AVAILA
315MHz/433MHz Low-Noise
Amplifier for Automotive RKE
Features
o
Optimized for 308MHz, 315MHz, 418MHz,
and 433.92MHz
o
2.2V to 5.5V Supply Voltage Range
o
Low Operating Supply Current
2.5mA (typ), 4mA (max)
o
Logic-Controlled 1µA (max) Shutdown
o
Typical Performance at 315MHz
1.25dB Noise Figure
-16dBm Input IP3
15.5dB Power Gain
o
Automotive Temperature Range
-40°C to +125°C
o
ESD Rating of ±2.5kV (HBM) on All Pins
o
AEC-Q100 Qualification
General Description
The MAX2634 low-noise amplifier (LNA) with low-power
shutdown mode is optimized for 315MHz and
433.92MHz automotive remote keyless entry (RKE)
applications. At 315MHz, the LNA achieves 15.5dB
power gain and a 1.25dB noise figure while only con-
suming 2.5mA of supply current from a 2.2V to 5.5V
power supply. An integrated logic-controlled low-power
shutdown mode reduces power consumption to 0.1µA
and replaces the two transistors typically required to
implement the shutdown function in discrete-based
RKE LNA solutions. The device further reduces compo-
nent count by integrating the output matching and DC-
blocking components, and only requires a single
inductor to match the input for best noise figure and
input return loss.
The device is available in a small 6-pin (2.0mm x
2.2mm x 0.9mm) lead-free SC70 package for automo-
tive applications that require visual inspection of PCB
solder connections.
MAX2634
Applications
Remote Keyless Entry (RKE)
Tire Pressure Monitoring Systems (TPMS)
Security
Garage Door Openers
Telemetry Receivers
TOP VIEW
GND
SHDN
GND
Ordering Information
PART
MAX2634AXT+
TEMP RANGE
-40°C to +125°C
PIN-
PACKAGE
6 SC70
TOP
MARK
+ADG
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Pin Configuration
+
1
2
3
MAX2634
6
5
4
RFOUT
V
CC
RFIN
SC70
Functional Diagram/Typical Operating Circuit appears at
end of data sheet.
Performance Table
FREQUENCY
(MHz)
308
315
418
433.92
L1
(nH)
56
56
33
33
SUPPLY
CURRENT
(mA)
2.5
2.5
2.5
2.5
GAIN
(dB)
15.5
15.5
13.5
13.5
NOISE FIGURE
(dB)
1.25
1.25
1.25
1.25
INPUT P1dB
(dBm)
-29
-29
-26
-26
INPUT IP3
(dBm)
-16
-16
-12
-12
________________________________________________________________
Maxim Integrated Products
1
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.
315MHz/433MHz Low-Noise
Amplifier for Automotive RKE
MAX2634
ABSOLUTE MAXIMUM RATINGS
V
CC
Pin to GND .....................................................-0.3V to +6.0V
RFIN.................Pin Must Be AC-Coupled with DC-Blocking Cap
RFOUT,
SHDN............................................-0.3V
to (V
CC
+ 0.3V)
RF Input Power .................................................................+5dBm
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SC70 (derate 3.1mW/°C above +70°C) ..............245mW
Junction-to-Case Thermal Resistance (θ
JC
)
(Note 1) ......................................................................115°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
)
(Note 1) ......................................................................326°C/W
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s)....................................300°C
Note 1:
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
www.maxim-ic.com/thermal-tutorial.
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
= +2.2V to +5.5V, T
A
= -40°C to +125°C, Typical values are at V
CC
= +3.0V, T
A
= +25°C, unless otherwise noted. RFIN and
RFOUT are AC-coupled and terminated to 50Ω. No RF input signals at RFIN and RFOUT.) (Note 2)
PARAMETER
Operating Supply Voltage
Operating Supply Current
Shutdown Supply Current
SHDN
= high, T
A
= +25°C
SHDN
= high, T
A
= -40°C to +125°C
V
SHDN
= 0, T
A
= +25°C
V
SHDN
= 0, T
A
= -40°C to +125°C
1.1
0.4
V
SHDN
= V
IH
V
SHDN
= V
IL
130
20
5
1
CONDITIONS
MIN
2.2
2.5
TYP
MAX
5.5
4
6
1
10
UNITS
V
mA
mA
µA
µA
V
V
µA
µA
µs
µs
DIGITAL CONTROL INPUTS (SHDN)
Digital Input-Voltage High
Digital Input-Voltage Low
Digital Input-Current High
Digital Input-Current Low
SHUTDOWN MODE CONTROL
Enable Time
Disable Time
2
_______________________________________________________________________________________
315MHz/433MHz Low-Noise
Amplifier for Automotive RKE
AC ELECTRICAL CHARACTERISTICS
(MAX2634 EV Kit, V
CC
= +2.2V to +5.5V, T
A
= -40°C to +125°C. Typical values are at V
CC
= +3.0V and T
A
= +25°C, unless otherwise
noted. P
RFIN
= -40dBm,
SHDN
= high.) (Note 2)
PARAMETER
f
RFIN
= 315MHz
Power Gain
Noise Figure
Input Third-Order Intercept Point
Input 1dB Compression Point
Input Return Loss
Output Return Loss
Reverse Isolation
f
RFIN
= 433.92MHz
Power Gain
Noise Figure
Input Third-Order Intercept Point
Input 1dB Compression Point
Input Return Loss
Output Return Loss
Reverse Isolation
T
A
= +25°C (Note 4)
T
A
= -40°C to +125°C, V
CC
= +3.0V (Note 4)
T
A
= +25°C
(Note 3)
11
10
1.25
-12
-26
11
8
60
13.5
dB
dB
dBm
dBm
dB
dB
dB
T
A
= +25°C
T
A
= -40°C to +125°C, V
CC
= +3.0V
T
A
= +25°C
(Note 3)
12.5
11.5
1.25
-16
-29
10
8
60
15.5
dB
dB
dBm
dBm
dB
dB
dB
CONDITIONS
MIN
TYP
MAX
UNITS
MAX2634
Note 2:
Guaranteed by production test at T
A
= +25°C. Guaranteed by design and characterization at T
A
= -40°C and T
A
= +125°C.
Note 3:
Measured with two tones located at 315MHz and 316MHz or 433MHz and 434MHz at -40dBm/tone.
Note 4:
Guaranteed by design and characterization.
Typical Operating Characteristics
(MAX2634 EV Kit, V
CC
= +2.2V to +5.5V, T
A
= -40°C to +125°C. Typical values are at V
CC
= +3.0V and T
A
= +25°C, unless otherwise
noted. f
RFIN
= 315MHz/433MHz, P
RFIN
= -40dBm,
SHDN
= high.)
S11, S22, S21 vs. FREQUENCY
(315MHz)
MAX2634 toc01
MAX2634 toc02
SUPPLY CURRENT vs. SUPPLY VOLTAGE
4.0
T
A
= +125°C
3.5
SUPPLY CURRENT (mA)
T
A
= +25°C
20
15
10
S11, S22, S21 (dB)
5
0
-5
-10
T
A
= -40°C
1.5
2.2
3.3
4.4
SUPPLY VOLTAGE (V)
5.5
-15
-20
200
S11, S22, S21 vs. FREQUENCY
(433MHz)
15
10
MAX2634 toc03
20
S21
S11, S22, S21 (dB)
3.0
S11
5
0
-5
-10
S21
S11
2.5
2.0
S22
300
400
500
FREQUENCY (MHz)
600
-15
S22
-20
200
300
400
500
FREQUENCY (MHz)
600
_______________________________________________________________________________________
3
315MHz/433MHz Low-Noise
Amplifier for Automotive RKE
MAX2634
Typical Operating Characteristics (contineed)
(MAX2634 EV Kit, V
CC
= +2.2V to +5.5V, T
A
= -40°C to +125°C. Typical values are at V
CC
= +3.0V and T
A
= +25°C, unless otherwise
noted. f
RFIN
= 315MHz/433MHz, P
RFIN
= -40dBm,
SHDN
= high.)
IIP3 vs. SUPPLY VOLTAGE
(315MHz)
MAX2634 toc04
IIP3 vs. SUPPLY VOLTAGE
(433MHz)
MAX2634 toc05
NOISE FIGURE vs. SUPPLY VOLTAGE
(433MHz)
T
A
= +125°C
2.0
NOISE FIGURE (dB)
T
A
= +25°C
1.5
MAX2634 toc06
-10
T
A
= +125°C
-12
-5
T
A
= +125°C
-8
T
A
= +25°C
2.5
IIP3 (dBm)
-16
T
A
= -40°C
IIP3 (dBm)
-14
T
A
= +25°C
-11
-14
1.0
-18
-17
T
A
= -40°C
0.5
T
A
= -40°C
0
2
3
4
5
SUPPLY VOLTAGE (V)
6
2
3
4
5
SUPPLY VOLTAGE (V)
6
-20
2
3
4
5
SUPPLY VOLTAGE (V)
6
-20
NOISE FIGURE vs. SUPPLY VOLTAGE
(315MHz)
MAX2634 toc07
GAIN vs. SUPPLY VOLTAGE
(433MHz)
MAX2634 toc08
GAIN vs. SUPPLY VOLTAGE
(315MHz)
T
A
= -40°C
16
15
GAIN (dB)
14
T
A
= +125°C
13
T
A
= +25°C
MAX2634 toc09
2.5
T
A
= +125°C
2.0
NOISE FIGURE (dB)
T
A
= +25°C
17
16
15
GAIN (dB)
14
13
T
A
= -40°C
17
1.5
T
A
= +25°C
1.0
0.5
T
A
= -40°C
0
2
3
4
5
SUPPLY VOLTAGE (V)
6
12
11
2
3
T
A
= +125°C
12
11
4
5
SUPPLY VOLTAGE (V)
6
2
3
4
5
SUPPLY VOLTAGE (V)
6
TURN-ON TIME
MAX2634 toc10
SHUTDOWN TIME
-30
-40
OUTPUT POWER (dBm)
-50
-60
-70
-80
-90
-100
-110
-120
1AVG
f
RFIN
= 315MHz
P
RFIN
= -43dBm
MAX2634 toc11
-20
-30
-40
OUTPUT POWER (dBm)
-50
-60
-70
-80
-90
-100
-110
-120
0
1AVG
f
RFIN
= 315MHz
P
RFIN
= -43dBm
-20
20 40 60 80 100 120 140 160 180 200
TIME (µs)
0
5
10 15 20 25 30 35 40 45 50
TIME (µs)
4
_______________________________________________________________________________________
315MHz/433MHz Low-Noise
Amplifier for Automotive RKE
Pin Description
PIN
1, 3
2
4
5
6
NAME
GND
SHDN
RFIN
V
CC
RFOUT
FUNCTION
Ground. Use minimum path to ground plane to minimize inductance.
Shutdown Input. A logic-level high enables the LNA, and a logic-level low disables the LNA.
RF Input. Requires an inductor to match the input for best noise figure and return loss. A DC-blocking
capacitor is required if the RFIN input will see a DC voltage or ground. See the
Functional
Diagram/Typical Operating Circuit.
Supply Voltage. Bypass to ground with a 0.01µF capacitor as close as possible to the pin.
RF Output. Internally matched to 50
and incorporates an internal DC-blocking capacitor.
MAX2634
Table 1. Typical Input and Output Impedances in R+jX Format
(V
CC
= +3.0V, T
A
= +25°C.)
FREQUENCY (MHz)
100
200
308
315
418
434
500
600
INPUT IMPEDANCE
R
58
43
29
29.4
29.2
28.5
26.4
26.7
X
-438
-216
-139
-137
-101
-96
-83
-69
R
92
92.1
91.2
91
90.5
89.5
91
87.5
OUTPUT IMPEDANCE
X
-94
-50
-35.8
-35
-30
-29.3
-28.2
-27.3
Detailed Description
The MAX2634 LNA with low-power shutdown mode is
optimized for 308MHz, 315MHz, 418MHz, and 433MHz
automotive RKE applications, which are required to
operate over the -40°C to +125°C automotive tempera-
ture range. The device reduces component count by
integrating the output matching and DC-blocking com-
ponents, and only requires a single inductor to match
the input for best noise figure and input return loss. An
integrated logic-controlled low-power shutdown mode
reduces power consumption to 0.1µA and replaces the
two transistors typically required to implement the shut-
down function in discrete-based RKE LNA solutions.
Input Matching
The MAX2634 requires an off-chip input matching net-
work. The
Functional Diagram/Typical Operating Circuit
shows the recommended input-matching network com-
ponent values for operation at 315MHz and 433MHz.
These values are optimized for the best simultaneous
gain, noise figure, and return loss performance. Table 1
lists typical input and output impedances.
_______________________________________________________________________________________
5
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