RF2418
LOW CURRENT LNA/MIXER
RoHS Compliant & Pb-Free Product
Package Style: SOIC-14
LNA
Features
Single 3V to 6.5V Power Sup-
ply
High Dynamic Range
Low Current Drain
High LO Isolation
LNA Power Down Mode for
Large Signals
LNA IN
1
GND
2
VDD1
3
VDD2
4
10pF
IF BYP
5
IF2 OUT
6
IF1 OUT
7
14
LNA OUT
13
GND
12
GND
11
RF IN
10
GND
9
DEC
8
LO IN
RF AMP
BUFFER
Applications
UHF Digital and Analog
Receivers
Digital Communication Sys-
tems
Spread-Spectrum Communi-
cation Systems
Commercial and Consumer
Systems
433MHz and 915MHz ISM
Band Receivers
General Purpose Frequency
Conversion
MIXER
Functional Block Diagram
Product Description
The RF2418 is a monolithic integrated UHF receiver front-end. The IC con-
tains all of the required components to implement the RF functions of the
receiver except for the passive filtering and LO generation. It contains an
LNA (low-noise amplifier), a second RF amplifier, a dual-gate GaAs FET
mixer, and an IF output buffer amplifier which will drive a 50Ω load. In
addition, the IF buffer amplifier may be disabled and a high impedance
output is provided for easy matching to IF filters with high impedances.
The output of the LNA is made available as an output to permit the inser-
tion of a bandpass filter between the LNA and the RF/Mixer section. The
LNA section may be disabled by removing the VDD1 connection to the IC.
Ordering Information
RF2418
RF2418PCBA-41X
Low Current LNA/Mixer
Fully Assembled Evaluation Board
Optimum Technology Matching® Applied
GaAs HBT
GaAs MESFET
InGaP HBT
SiGe BiCMOS
Si BiCMOS
SiGe HBT
GaAs pHEMT
Si CMOS
Si BJT
GaN HEMT
RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trade-
mark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2006, RF Micro Devices, Inc.
Rev A7 DS060203
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
1 of 12
RF2418
Absolute Maximum Ratings
Parameter
Supply Voltage
Input LO and RF Levels
Ambient Operating Temperature
Storage Temperature
Rating
-0.5 to 7
+6
-40 to +85
-40 to +150
Unit
V
DC
dBm
°C
°C
Caution! ESD sensitive device.
Exceeding any one or a combination of the Absolute Maximum Rating conditions may
cause permanent damage to the device. Extended application of Absolute Maximum
Rating conditions to the device may reduce device reliability. Specified typical perfor-
mance or functional operation of the device under Absolute Maximum Rating condi-
tions is not implied.
RoHS status based on EUDirective2002/95/EC (at time of this document revision).
The information in this publication is believed to be accurate and reliable. However, no
responsibility is assumed by RF Micro Devices, Inc. ("RFMD") for its use, nor for any
infringement of patents, or other rights of third parties, resulting from its use. No
license is granted by implication or otherwise under any patent or patent rights of
RFMD. RFMD reserves the right to change component circuitry, recommended appli-
cation circuitry and specifications at any time without prior notice.
Parameter
Overall
RF Frequency Range
Cascade Power Gain
Cascade IP
3
Cascade Noise Figure
Min.
Specification
Typ.
Max.
Unit
Condition
T = 25°C, V
CC
=5V, RF=850MHz,
LO=921MHz
400 to 1100
23
-13
2.4
MHz
dB
dBm
dB
High impedance output
Referenced to the input
Single sideband, includes image filter with
1.0dB insertion loss
First Section (LNA)
Noise Figure
Input VSWR
Input IP3
Gain
Reverse Isolation
Output VSWR
+3.0
13
1.8
1.5:1
+4.0
14
40
1.5:1
High impedance output
9.5
1.5:1
+1
7
9
4000||10pF
dBm
dB
Ω
Open Collector
Buffered output, 50Ω load
10
1.5:1
-0.5
5
0
6
30
dBm
dB
Ω
dB
Single Sideband
With external series matching inductor
dB
Single Sideband
With external series matching inductor
dBm
dB
dB
2.0
dB
With external series matching inductor
Second Section (RF Amp,
Mixer, IF1)
Noise Figure
Input VSWR
Input IP3
Conversion Power Gain
Output Impedance
Second Section (RF Amp,
Mixer, IF2)
Noise Figure
Input VSWR
Input IP3
Conversion Gain
Output Impedance
2 of 12
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
Rev A7 DS060203
RF2418
Parameter
LO Input
LO Frequency
LO Level
LO to RF Rejection
LO to IF Rejection
LO Input VSWR
300 to 1200
-6 to +6
15
40
1.3:1
MHz
dBm
dB
dB
With pin 5 connected to ground.
In order to achieve a low VSWR match at this
input, an 82Ω resistor to ground is placed in
parallel with this port.
6.5
14
12
6
20
9
26
20
V
mA
mA
mA
V
CC
=5.0V, LNA On, Mixer On, Buffer Off
V
CC
=5.0V, LNA On, Mixer On, Buffer On
V
CC
=5.0V, LNA Off, Mixer On, Buffer Off
Min.
Specification
Typ.
Max.
Unit
Condition
Power Supply
Voltage
Current Consumption
3.0
Rev A7 DS060203
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
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RF2418
Pin
1
Function
LNA IN
Description
A series 10nH matching inductor is necessary to achieve specified gain
and noise figure at 900MHz. This pin is NOT internally DC-blocked. An
external blocking capacitor must be provided if the pin is connected to a
device with DC present. A DC path to ground (i.e. an inductor or resistor to
ground) is, however, acceptable at this pin. If a blocking capacitor is
required, a value of 22pF is recommended.
Interface Schematic
LNA IN
2
3
GND
VDD1
Ground connection. Keep traces physically short and connect immediately
to ground plane for best performance.
Supply Voltage for the LNA only. A 22pF external bypass capacitor is
required and an additional 0.01μF is required if no other low frequency
bypass capacitors are near by. The trace length between the pin and the
bypass capacitors should be minimized. The ground side of the bypass
capacitors should connect immediately to ground plane.
For large input signals, VDD1 may be disconnected, resulting in the LNA’s
gain changing from +11dB to -26dB and current drain decreasing by 4mA.
If the LNA is never required for use, then this pin can be left unconnected
or grounded, and Pin 11 is used as the first input.
Power supply for the IF buffer amplifier. If the high impedance mixer output
is being used, then this pin is not connected.
If this pin is connected to ground, an internal 10pF capacitor is connected
in parallel with the mixer output. This capacitor functions as an LO trap,
which reduces the amount of LO to IF bleed-through and prevents high LO
voltages at the mixer output from degrading the mixer’s dynamic range. At
higher IF frequencies, this capacitance, along with parasitic layout capaci-
tance, should be parallel resonated out by the choice of the bias inductor
value at pin 7. If the internal capacitor is not connected to ground, the
buffer amplifier could become unstable. A ~10pF capacitor should be
added at the output to maintain the buffer’s stability, but the gain will not
be significantly affected.
50Ω buffered (open source) output port, one of two output options. Pin 7
must have a bias resistor to V
DD
and pin 6 must have a bias resistor to
ground (see Buffered Output Application Schematic) in order to turn the
buffer amplifier on. Current drain will increase by approximately 8mA at
5V, and by approximately 5mA at 3V. It is recommended that these bias
resistors be less than 1kΩ.
High impedance (open drain) output port, one of two output options. This
pin must be connected to V
DD
through a resistor or inductor in order to
bias the mixer, even when using IF2 Output. In addition, a 0.01μF bypass
capacitor is required at the other end of the bias resistor or inductor. The
ground side of the bypass capacitor should connect immediately to ground
plane. This output is intended to drive high impedance IF filters. The rec-
ommended matching network is shunt L, series C (see the application
schematic, high impedance output). This topology will provide matching,
bias, and DC-blocking.
Mixer LO input. A high-pass matching network, such as a single shunt
inductor (as shown in the application schematics), is the recommended
topology because it also rejects IF noise at the mixer input. This filtering is
required to achieve the specified noise figures. This pin is NOT internally
DC-blocked. An external blocking capacitor must be provided if the pin is
connected to a device with DC present. A DC path to ground (i.e. an induc-
tor or resistor to ground) is, however, acceptable at this pin. If a blocking
capacitor is required, a value of 22pF is recommended.
Connection for the external bypass capacitor for the mixer RF input
preamp. 1000pF is recommended. The trace length between the pin and
the capacitor should be minimized. The ground side of the bypass capaci-
tor should connect immediately to ground plane.
4
5
VDD2
IF BYP
6
IF2 OUT
IF2 OUT
7
IF1 OUT
IF1 OUT
8
LO IN
LO IN
9
RF BYP
4 of 12
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
Rev A7 DS060203
RF2418
Pin
10
11
Function
GND
RF IN
Description
Same as pin 2.
Mixer RF Input port. For a 50Ω match at 900MHz use a 15nH series
inductor. This pin is NOT internally DC-blocked. An external blocking capac-
itor must be provided if the pin is connected to a device with DC present. A
DC path to ground (i.e. an inductor or resistor to ground) is, however,
acceptable at this pin. If a blocking capacitor is required, a value of 22pF is
recommended.To minimize the mixer’s noise figure, it is recommended to
have a RF bandpass filter before this input. This will prevent the noise at
the image frequency from being converted to the IF.
Same as pin 2.
Same as pin 2.
50Ω output. Internally DC-blocked.
LNA OUT
Interface Schematic
R F IN
12
13
14
GND
GND
LNA OUT
Package Drawing
0.156
0.148
.018
.014
0.010
0.004
0.347
0.339
0.050
0.252
0.236
0.059
0.057
8° MAX
0° MIN
0.0500
0.0164
0.010
0.007
Rev A7 DS060203
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
5 of 12
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