RF2878 - RFMD.com

RF2878
3V LOW NOISE AMPLIFIER/
3V PA DRIVER AMPLIFIER
Package Style: SOT 5-Lead
Features





Low Noise and High Intercept
Point
Adjustable Bias Current
Power Down Control
Single 2.5V to 5.0V Power
Supply
150MHz to 2500MHz Operation
Applications




CDMA/FM Cellular PCS LNA
Low Noise Transmit Driver
Amplifier
General Purpose Amplification
Commercial and Consumer
Systems
RF IN
1
GND1
2
VPD
3
5
GND2
4
RF OUT
Functional Block Diagram
Product Description
The RF2878 is a low noise amplifier with a very high dynamic range designed for
digital cellular applications. The device functions as an outstanding front end low
noise amplifier or power amplifier driver amplifier in the transmit chain of digital
subscriber units where low transmit noise power is a concern. When used as an
LNA, the bias current can be set externally. When used as a PA driver, the IC can
operate directly from a single cell Li-ion battery and includes a power down feature
that can be used to completely turn off the device. The IC is featured in a standard
SOT 5-lead plastic package.
Ordering Information
RF2878
RF2878SR
RF2878TR7
RF2878PCK-410

GaAs HBT
GaAs MESFET
InGaP HBT
Sample bag with 25 pieces
7" Sample reel with 100 pieces
7" Reel with 2500 pieces
1800MHz to 2170MHz PCBA with 5-piece sample bag
Optimum Technology Matching® Applied
SiGe BiCMOS
Si BiCMOS
SiGe HBT
GaAs pHEMT
Si CMOS
Si BJT
GaN HEMT
RF MEMS
RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark 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.
DS111104
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support, contact RFMD at (+1) 336-678-5570 or [email protected].
1 of 14
RF2878
Absolute Maximum Ratings
Parameter
Supply Voltage, VCC
Rating
Unit
<5
V
Power Down Voltage, VPD
<3
V
Input RF Level
+10
dBm
Operating Ambient Temperature
-40 to +85
°C
Storage Temperature
-40 to +150
°C
Operating Junction Temperature
150
°C
ICC
30
mA
Parameter
Min.
Specification
Typ.
Max.
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 performance or functional operation of the device under Absolute Maximum Rating conditions 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 application circuitry and specifications at any time without prior notice.
Unit
Condition
Overall
RF Frequency Range
150
2500
MHz
Schematic per LNA Application;
T=25°C, RF=881MHz, VPD =2.8V,
R1=1k
Low Noise Amplifier
881MHz Performance
Gain
Noise Figure
Input IP3
20
dB
20
dB
VCC =2.7V, ICC =7.5mA
dB
VCC =3.0V, ICC =7.6mA
1.4
1.6
1.4
1.6
dB
VCC =2.7V, ICC =7.5mA
+6.0
dBm
VCC =3.0V, ICC =7.6mA
+5.5
dBm
VCC =2.7V, ICC =7.5mA
Low Noise Amplifier
1950MHz Performance
Schematic per LNA Application;
T=25°C, RF=1950MHz, VPD =2.8V, R1=1k
Gain
Noise Figure
Input IP3
Output IP3
Noise Figure
Reverse Isolation
2 of 14
VCC =3.0V, ICC =6.4mA
13
dB
13
dB
VCC =2.7V, ICC =6.3mA
dB
VCC =3.0V, ICC =6.4mA
1.3
1.5
1.3
1.5
dB
VCC =2.7V, ICC =6.3mA
+16.5
dBm
VCC =3.0V, ICC =6.4mA
+16.0
dBm
VCC =2.7V, ICC =6.3mA
Driver Amplifier
836MHz Performance
Gain
VCC =3.0V, ICC =7.6mA
Schematic per Driver Amplifier Application;
T=25°C, RF=836MHz, VPD =2.8V
19.5
20.5
21.5
dB
VCC =3.5V
19.5
20.5
21.5
dB
VCC =3.0V
19.5
20.5
21.5
dB
VCC =2.7V
25
+32.0
35
dBm
VCC =3.5V
+29.0
dBm
VCC =3.0V
+27.8
dBm
VCC =2.7V
1.9
2.0
dB
VCC =3.5V
1.85
2.0
dB
VCC =3.0V
1.8
2.0
dB
VCC =2.7V
25
dB
VCC =3.5V
25
dB
VCC =3.0V
25
dB
VCC =2.7V
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
DS111104
RF2878
Specification
Typ.
Max.
Input VSWR
1.8:1
2.0:1
Output VSWR
1.25:1
2.0:1
Parameter
Min.
Unit
Condition
Driver Amplifier
836MHz Performance, cont.
P1dB
Using External LC network used on evaluation
board.
14.4
dBm
VCC =3.5V
12.5
dBm
VCC =3.0V
11.5
dBm
VCC =2.7V
3.5
V
Power Supply
T = 25 °C
Voltage (VCC)
Voltage (VPD)
Current Consumption Driver Amplifier (see note 1)
2.8
14.0
21.5
Power Down
V
29.0
mA
10
A
Driver Amplifier
1880MHz Performance
Output IP3
Noise Figure
Reverse Isolation
14.0
dB
VCC =3.5V
14.0
dB
VCC =3.0V
14.0
dB
VCC =2.7V
+35.0
dBm
VCC =3.5V
+31.0
dBm
VCC =3.0V
+28.8
dBm
VCC =2.7V
VCC =3.5V
1.85
2.0
dB
1.8
2.0
dB
VCC =3.0V
1.75
2.0
dB
VCC =2.7V
19
dB
VCC =3.5V
19
dB
VCC =3.0V
dB
VCC =2.7V
19
Input VSWR
1.6:1
2.0:1
Output VSWR
1.6:1
2.0:1
Using External LC network used on evaluation
board.
14
15.6
dBm
13
14.1
dBm
VCC =3.0V
12
13.1
dBm
VCC =2.7V
3.5
V
Power Supply
Voltage (VPD)
Power Down
VCC =3.5V
T = 25 °C
Voltage (VCC)
Current Consumption Driver Amplifier (see note 2)
VCC =3.5V; VPD  0.9 V
Schematic per Driver Amplifier Application;
T=25°C, RF=1880MHz, VPD =2.8V
Gain
P1dB
VCC =3.5V; VPD =2.8V
2.8
14
21
V
29
mA
VCC =3.5V; VPD =2.8V
10
A
VCC =3.5V; VPD  0.9 V
Note 1: Current consumption shown for ICC only. IPD typical=2.0mA with VPD =2.8V
DS111104
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support, contact RFMD at (+1) 336-678-5570 or [email protected].
3 of 14
RF2878
Pin
1
Function
RF IN
Description
Interface Schematic
RF input pin. This pin is DC coupled and matched to 50 at 836 MHz.
To Bias
Circuit
RF OUT
RF IN
2
GND1
3
VPD
Ground connection. Keep traces physically short and connect immediately to ground
plane for best performance.
For low noise amplifier applications, this pin is used to control the bias current. See plots
for bias current settings. An external resistor (R1) can be used to set the bias current for
any VPD voltage.
PD
For driver amplifier applications, this is the Power Down pin for the IC. VPD =2.8V +/0.1V is required for proper operation. VPD< 0.9V turns off the Part. External RF bypassing is required. 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. Nominal current required for VPD =2.8V is 2.0mA typical and 3.0mA Max
(@ VPD =2.9V).
4
RF OUT
5
GND2
Amplifier Output pin. This pin is an open-collector output. It must be biased to either VCC
or pin 4 through a choke or matching inductor. This pin is typically matched to 50 with
a shunt bias/matching inductor and series blocking/matching capacitor. Refer to application schematics.
Ground connection. Keep traces physically short and connect immediately to ground
plane for best performance.
Package Drawing
-A1.14±.15
1.60±.10
.15
.05
.520
.360
TYP
10°
TYP
2.90±.10
.950
1.44
1.04
2.80±.20
3°MAX
0°MIN
.127
TYP
.45±.10
Notes:
1.Shaded Lead is Pin 1.
2.Dimensions do not influde mold flash, protrusions or burrs.
3.:ead Dimensions include solder plating.
4.Foot Length measured reference to flat foot surface parallel to datum “A”.
5.Package is die down configuration.
4 of 14
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support, contact RFMD at (+1) 336-678-5570 or [email protected].
DS111104
RF2878
Application Schematic:
350MHz LNA
22 nF
J1
RF IN
1
5
2
4 pF
1 k
VPD
VCC=3.5V, VPC=2.8V
ICC=7mA
Gain=25.5dB
NF=1.75dB
IIP3=-4.5dBm
S11=-2.8dB
S22=-10.4dB
3
10 nF
J2
RF OUT
4
220 pF
39 nH
VCC
220 pF
10 nF
Application Schematic:
350MHz Linear Driver
50  strip
J1
RF IN
C3
22 nF
1
5
56 nH
2
VPD
R1
0
3
C1
10 nF
C2
220 pF
VCC=3.5V, VPC=2.7V
ICC=20mA
Gain=26dB
OIP3=27.5dBm
OP1dB=13.8dBm
S11=S22=-14dB
50  strip
4
510 
4.3 pF
50  strip
J2
RF OUT
39 nH
VCC
C5
220 pF
DS111104
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
C6
10 nF
5 of 14
RF2878
Application Schematic:
1200MHz to 1600MHz Driver
(set resistance at VPD=1000 for LNA)
22 nF
J1
RF IN
1
5
2
VPD
1.5 pF
0
10 nF
VCC=3.5V, VPC=2.7V
ICC=21mA
Gain=17dB to 14.2dB from 1200MHz to 1600MHz
S11=-8.7dB to -23dB from 1200MHz to 1600MHz
S22=-14.5dB to -8.1dB from 1200MHz to 1600MHz
3
J2
RF OUT
4
100 pF
6.8 nH
VCC
100 pF
10 nF
Application Schematic:
1800MHz to 2170MHz Linear Driver
(set resistance at VPD=1000 for LNA)
22 nF
J1
RF IN
1
5
2
VPD
1 pF
0
10 nF
VCC=4V, VPC=2.7V
ICC=21mA
Gain=13.8dB to 12.3dB from1800MHz to 2170MHz
S11=-11dB to -20dB from1800MHz to 2170MHz
S22=-11.5dB to -12.5dB from1800MHz to 2170MHz
OIP3=36dBmto 34.5dBmfrom1800MHz to 2170MHz
OP1dB=16dBm to 17dBmfrom1800MHz to 2170MHz
3
100 pF
2.7 nH
**47 dropping R for use with VCC=5V.
5-0.021*47=4V at RF2878 collector
6 of 14
J2
RF OUT
4
**47 
100 pF
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
VCC
10 nF
DS111104
RF2878
Application Schematic:
Low Noise Amplifier ~1950MHz Operation
22 nF
J1
RF IN
1
5
2
VPD
1 pF
1k 
3
10 nF
J2
RF OUT
4
100 pF
3.3 nH
VCC
100 pF
10 nF
Application Schematic:
Driver Amplifier ~1880MHz Operation
22 nF
J1
RF IN
1
5
2
VPD
1 pF
0
3
10 nF
100 pF
J2
RF OUT
4
3.3 nH
VCC
100 pF
DS111104
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
10 nF
7 of 14
RF2878
Evaluation Board Schematic:
Low Noise Amplifier ~881MHz Operation
P1
P1-1
1
VPD
2
GND
3
VCC
C7
4.7 F
J1
RF IN
50  strip
C3
22 nF
1
5
2
VPD
R1
1k 
3
C1
10 nF
4
C2
220 pF
C4
2 pF
50  strip
50  strip
L1
12 nH
2361410 Rev-
J2
RF OUT
VCC
C5
220 pF
C6
10 nF
Evaluation Board Schematic:
Driver Amplifier ~836MHz Operation
P1
P1-1
1
VPD
2
GND
3
VCC
C7
4.7 F
J1
RF IN
50  strip
C3
22 nF
1
5
2
VPD
R1
0
3
C1
10 nF
4
C2
220 pF
C4
2 pF
50  strip
50  strip
L1
12 nH
2361400 Rev-
VCC
C5
220 pF
8 of 14
J2
RF OUT
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
C6
10 nF
DS111104
RF2878
Evaluation Board Layout - 900MHz Driver
Board Size 0.948” x 1.063”
Board Thickness 0.031”; Board Material FR-4
Evaluation Board Layout - 900MHz LNA
DS111104
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
9 of 14
RF2878
Theory of Operation
This section will focus on a variety of applications outside the nominal, for the purpose of demonstrating RF2878 versatility.
Application schematics pertaining to topics discussed can be found within the data sheet for reference.
First, an application for linear driver, covering 1800MHz to 2170MHz. Operating condition:
VCC =4V
VPD =2.7V
ICC =21mA
Note 0 value for bias resistor at VPD in the application schematic, set for increased current/IP3. Typical specs are listed along
with schematic. VCC =4V contributes to enhanced compression point (16dBm to 17dBm). Junction temperature seen for ambient condition=85°C will be a consideration in setting VCC/VPD. The above biasing condition yields TJ =132°C. Thus, the conditions chosen allow for highly reliable operation while providing impressive linear performance.
Using a 5V supply rail is often convenient from a design standpoint. In the 1800MHz to 2170MHz driver application already
discussed, VCC =4V is recommended in order to maintain highest reliability. An option for using VCC =5V is shown in the application schematic. Use of a simple dropping resistor at VCC provides 4.0V at output collector, resulting in the suggested device
operating condition. Power dissipation in the resistor=0.021 Watt, easily handled by standard resistors available to the system
designer.
Moving to another application, consider the schematic for 350MHz LNA. Noise figure in this case=1.75dB. In contrast to
above linear driver, bias resistor is set at 1000 to limit current. In the specifications next to schematic, see that input return
loss is somewhat degraded at 2.8dB. The absence of input matching is intentional, as the integrated circuit design was geared
for optimum noise figure with input looking back into 50. Note that in the nominal cases, 881MHz and 1950MHz, input
return losses are favorable in the absence of input match.
In converting 350MHz LNA to driver, noise figure will no longer be a key specification. As such, RF2878 device s-parameter
data can be used to match input for favorable return loss. The resulting driver application schematic is found below that for the
LNA. When matching in bands other than those covered here, RF2878 S-parameter data can be obtained through applications/sales contact at RFMD.
As a final example, refer to driver application schematic covering 1200MHz to 1600MHz. This match provides favorable return
losses over the entire band.
In summary, the examples above are intended to aid the system designer in determining suitable matches and device operating points for both LNA and driver applications. Key points to consider:
1. In setting bias condition to accommodate both LNA and driver, the first consideration is choice of bias resistance at VPC.
Linearity versus power dissipation trade-offs are taken into account in the driver application.
2. Noise figure versus input return loss trade-off must be considered in the specific case of low frequency LNA application.
Driver application here allows for flexibility in optimizing input match for return loss.
3. Higher frequency LNA sees favorable return loss in the absence of input match. Thus, optimization at frequency >800MHz
involves matching adjust to output L-C only.
4. Small signal S-parameter simulation proves an excellent method for obtaining starting point matches in the design process.
10 of 14
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
DS111104
RF2878
Driver Amp 836 MHz
ICC versus VPD
26.0
20.92
2.7V Icc (mA)
3.0V Icc (mA)
3.3V Icc (mA)
3.6V Icc (mA)
25.5
25.0
24.5
20.90
20.88
24.0
Driver Amp 836 MHz
Gain versus VPD
2.7V Gain (dB)
3.0V Gain (dB)
3.3V Gain (dB)
3.6V Gain (dB)
20.86
Gain (dB)
ICC (mA)
23.5
23.0
22.5
22.0
20.84
20.82
20.80
21.5
21.0
20.78
20.5
20.76
20.0
20.74
19.5
19.0
20.72
2.7
2.8
2.9
3.0
2.70
2.80
VPD
Driver Amp 836 MHz
OIP3 versus VPD
33.0
3.00
Driver Amp 836 MHz
POUT 1dB versus VPD
15.0
2.7V OIP3 (dBm)
3.0V OIP3 (dBm)
3.3V OIP3 (dBm)
3.6V OIP3 (dBm)
32.0
14.5
2.7V P 1dB (dBm)
3.0V P 1dB (dBm)
3.3V P 1dB (dBm)
3.6V P 1dB (dBm)
14.0
POUT 1dB (dBm)
31.0
OIP3 (dBm)
2.90
VPD
30.0
13.5
13.0
12.5
29.0
12.0
28.0
11.5
27.0
11.0
2.7
2.8
2.9
3.0
VPD
2.05
2.00
2.7
2.8
2.9
3.0
VPD
Driver Amp 836 MHz
Noise Figure versus VPD
2.7V NF (dB)
3.0V NF (dB)
3.3V NF (dB)
3.6V NF (dB)
NF (dB)
1.95
1.90
1.85
1.80
1.75
1.70
2.70
2.80
2.90
3.00
VPD
DS111104
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
11 of 14
RF2878
Low Noise Amplifier 881 MHz
Gain versus ICC
19.95
2.7V Gain (dB)
3.0V Gain (dB)
3.3V Gain (dB)
3.6V Gain (dB)
19.90
Low Noise Amplifier 881 MHz
OIP3 versus ICC
29.0
2.7V OIP3 (dBm)
3.0V OIP3 (dBm)
3.3V OIP3 (dBm)
3.6V OIP3 (dBm)
28.5
28.0
19.85
27.5
OIP3 (dBm)
Gain (dB)
19.80
19.75
19.70
27.0
26.5
26.0
25.5
19.65
25.0
19.60
24.5
19.55
6.00
24.0
6.50
7.00
7.50
8.00
8.50
9.00
9.50
10.00
6.0
6.5
7.0
7.5
ICC
Low Noise Amplifier 881 MHz
IIP3 versus ICC
9.0
8.0
8.5
9.0
9.5
10.0
9.5
10.0
Low Noise Amplifier 881 MHz
POUT 1dB versus ICC
13.5
2.7V IIP3 (dBm)
3.0V IIP3 (dBm)
3.3V IIP3 (dBm)
3.6V IIP3 (dBm)
8.5
8.0
ICC (mA)
2.7V Pout 1dB (dBm)
3.0V Pout 1dB (dBm)
3.3V Pout 1dB (dBm)
3.6V Pout 1dB (dBm)
13.0
12.5
POUT 1dB (dBm)
IIP3 (dBm)
7.5
7.0
6.5
6.0
12.0
11.5
11.0
5.5
10.5
5.0
10.0
4.5
4.0
9.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
ICC (mA)
6.0
6.5
7.0
7.5
8.0
8.5
9.0
ICC (mA)
Low Noise Amplifier 881 MHz
Noise Figure versus ICC
1.42
2.7V NF (dB)
3.0V NF (dB)
3.3V NF (dB)
3.6V NF (dB)
1.41
1.40
NF (dB)
1.39
1.38
1.37
1.36
1.35
1.34
1.33
6.00
6.50
7.00
7.50
8.00
8.50
9.00
9.50
10.00
ICC
12 of 14
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
DS111104
RF2878
PCB Design Requirements
PCB Surface Finish
The PCB surface finish used for RFMD's qualification process is electroless nickel, immersion gold. Typical thickness is 3inch
to 8inch gold over 180inch nickel.
PCB Land Pattern Recommendation
PCB land patterns are based on IPC-SM-782 standards when possible. The pad pattern shown has been developed and tested
for optimized assembly at RFMD; however, it may require some modifications to address company specific assembly processes. The PCB land pattern has been developed to accommodate lead and package tolerances.
PCB Metal Land Pattern
A = 0.70 x 1.00 (mm) Typ.
Dimensions in mm.
Pin 5
Pin 1
A
A
0.95 Typ.
1.90 Typ.
A
A
A
2.60
Figure 1. PCB Metal Land Pattern (Top View)
DS111104
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
13 of 14
RF2878
PCB Solder Mask Pattern
Liquid Photo-Imageable (LPI) solder mask is recommended. The solder mask footprint will match what is shown for the PCB
metal land pattern with a 2mil to 3mil expansion to accommodate solder mask registration clearance around all pads. The
center-grounding pad shall also have a solder mask clearance. Expansion of the pads to create solder mask clearance can be
provided in the master data or requested from the PCB fabrication supplier.
A = 0.90 x 1.20 (mm) Typ.
Dimensions in mm.
Pin 5
Pin 1
A
A
0.95 Typ.
1.90 Typ.
A
A
A
2.60
Figure 2. PCB Solder Mask (Top View)
RoHS* Banned Material Content
RoHS Compliant:
Yes
Package total weight in grams (g):
0.014
Compliance Date Code:
NA
Bill of Materials Revision:
-
Pb Free Category:
Bill of Materials
e3
Parts Per Million (PPM)
Pb
Cd
Hg
Cr VI
PBB
PBDE
Die
0
0
0
0
0
0
Molding Compound
0
0
0
0
0
0
Lead Frame
0
0
0
0
0
0
Die Attach Epoxy
0
0
0
0
0
0
Wire
0
0
0
0
0
0
Solder Plating
0
0
0
0
0
0
This RoHS banned material content declaration was prepared solely on information, including analytical data, provided to RFMD by its
suppliers, and applies to the Bill of Materials (BOM) revision noted above.
* DIRECTIVE 2002/95/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 27 January 2003 on the restriction of the use of
certain hazardous substances in electrical and electronic equipment
14 of 14
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected].
DS111104