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Product Description
Ordering Information
Typical Applications
Features
Functional Block Diagram
RF Micro Devices, Inc.
7628 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
Optimum Technology Matching Applied
Si BJT
GaAs MESFET
GaAs HBT
Si Bi-CMOS
SiGe HBT
Si CMOS
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
NC
VCC1
VCC2
GND
GND
GND1
RF IN
PD
G16
G8
RF OUT
GND
GND
RF OUT
NC
NC
RF2155
3V PROGRAMMABLE GAIN POWER AMPLIFIER
Analog Communication Systems
900MHz Spread Spectrum Systems
400MHz Industrial Radios
Driver Stage for Higher Power Applications
3V Applications
The RF2155 is a 3 V medium power programmable gain
amplifier IC. The device is manufactured on an advanced
Gallium Arsenide Heterojunction Bipolar Transistor (HBT)
process, and has been designed for use as the final RF
amplifier in analog cellular phone transmitters or ISM
applications operating at 915MHz. The device is self-con-
tained with the exception of the output matching network
and power supply feed line. A two-bit digital control pro-
vides 4 levels of power control, in 8dB steps.
Single 3V Supply
500mW CW Output Power
31dB Small Signal Gain
Up to 60% Efficiency
Digitally Controlled Output Power
430MHz to 930MHz Frequency Range
RF2155
3V Programmable Gain Power Amplifier
RF2155 PCBA
Fully Assembled Evaluation Board
2
Rev B3 010417
0.035
0.016
0.010
0.008
8 MAX
0 MIN
0.021
0.014
0.392
0.386
0.158
0.150
0.244
0.230
0.069
0.064
0.050
0.060
0.054
-A-
0.009
0.004
Package Style: Standard Batwing
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RF2155
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Absolute Maximum Ratings
Parameter
Rating
Unit
Supply Voltage
-0.5 to +5.5
V
DC
Power Down Voltage (V
PD
)
-0.5 to +3.3
V
DC Supply Current
500
mA
Input RF Power
+10
dBm
Output Load VSWR
10:1
Ambient Operating Temperature
-30 to +85
C
Storage Temperature
-40 to +150
C
Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Overall
T = 25 C, V
CC
= 3.6V, V
PD
= 3.0V,
Z
LOAD
= 13
, P
IN
=0dBm, Freq=915MHz
Frequency Range
430 to 930
MHz
Maximum CW Output Power
450
mW
V
CC
= 3.6V
300
mW
V
CC
= 3.0V
Small Signal Gain
31
dB
Second Harmonic
-30
dBc
Without external second harmonic trap
Third Harmonic
-40
dBc
Fourth Harmonic
-36
dBc
Input VSWR
2:1
All gain settings
CW Efficiency
50
56
%
G16= "high", G8= "high", P
IN
=0dBm
Output Load VSWR
6:1
Spurious<-60dBc
Power Control
Power Down "ON"
2.7
2.8
3.0
V
Voltage supplied to the input
Power Down "OFF"
0
0.5
0.8
V
Voltage supplied to the input
PD Input Current
3.7
5.0
mA
Only in "ON" state
G16, G8 "ON"
2.2
2.5
3.0
V
Voltage supplied to the input
G16, G8 "OFF"
0
0.3
0.5
V
Voltage supplied to the input
G16, G8 Input Current
0.8
1.0
1.6
mA
Only in "ON" state
Output Power
+25.5
+26.5
+28.0
dBm
G16= "high", G8= "high", P
IN
=0dBm
+16.0
+18.5
+21.0
dBm
G16= "high", G8= "low", P
IN
=0dBm
+8.0
+10.5
+13.0
dBm
G16= "low", G8= "high", P
IN
=0dBm
-1.0
+1.5
+4.0
dBm
G16= "low", G8= "low", P
IN
=0dBm
Turn On/Off Time
100
ns
Power Supply
Power Supply Voltage
3.6
V
Specifications
3.0
5.0
V
Operating limits
Power Supply Current
225
300
mA
G16= "high", G8= "high", P
IN
=0dBm
90
115
mA
G16= "high", G8= "low", P
IN
=0dBm
37
55
mA
G16= "low", G8= "high", P
IN
=0dBm
25
35
mA
G16= "low", G8= "low", P
IN
=0dBm
20
50
110
mA
G16= "high", G8= "high", No RF In
1
10
A
G16= "low", G8= "low", PD= "low"
Caution! ESD sensitive device.
RF Micro Devices believes the furnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
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Pin
Function
Description
Interface Schematic
1
NC
Not internally connected.
2
VCC1
Positive supply for the first stage (driver) amplifier. This is an
unmatched transistor collector output. This pin should see an inductive
path to AC ground (V
CC
with a UHF bypassing capacitor). This induc-
tance can be achieved with a short, thin microstrip line (approximately
equivalent to 0.4nH). At lower frequencies, the inductance value should
be larger (longer microstrip line) and V
CC
should be bypassed with a
larger bypass capacitor. This inductance forms a matching network
with the amplifier stages, setting the amplifier's frequency of maximum
gain. An additional 1
F bypass capacitor in parallel with the UHF
bypass capacitor is also recommended, but placement of this compo-
nent is not as critical. A resistor of 39
from this pin to pin 3 is neces-
sary to ensure stability under extreme output VSWR conditions.
3
VCC2
Positive supply for the bias circuits. This pin should be bypassed with a
single UHF capacitor, placed as close as possible to the package.
4
GND
Ground connection. Keep traces physically short and connect immedi-
ately to the ground plane for best performance.
5
GND
Same as pin 4.
6
GND1
Ground return for the first stage; this should be connected to a via very
close to the device.
7
RF IN
Amplifier RF input. This is a 50
RF input port to the amplifier. To
improve the input match over all four gain control settings, an input
inductor of 6.8nH should be added. The amplifier does not contain
internal DC blocking and, therefore, should be externally DC blocked
before connecting to any device which has DC present or which con-
tains a DC path to ground. A series UHF capacitor is recommended for
the DC blocking.
See pin 2.
8
PD
Power down control voltage. When this pin is at 0V, the device will be in
power down mode, dissipating minimum DC power. When this pin is at
3V the device will be in full power mode delivering maximum available
gain and output power capability. This pin should not, in any circum-
stance, be higher than 3.3V. This pin should also have an external UHF
and HF bypassing capacitor.
9
NC
Not internally connected.
10
NC
Not internally connected.
11
RF OUT
Amplifier RF output. This is an unmatched collector output of the final
amplifier transistor. It is internally connected to pins 11 and 14 to pro-
vide low series inductance and flexibility in output matching. Bias for
the final power amplifier output transistor must also be provided
through one of these pins. Typically, pin 14 is used to supply bias. A
transmission line of approximately 500mils length, followed by a
bypass capacitor, is adequate. This pin can also be used to create a
second harmonic trap. A UHF and large tantalum (1
F) capacitor
should be placed on the power supply side of the bias inductor. Pin 11
should be used for the RF output with a matching network that presents
the optimum load impedance to the PA for maximum power and effi-
ciency, as well as providing DC blocking at the output.
12
GND
Same as pin 4.
13
GND
Same as pin 4.
14
RF OUT
Same as pin 11.
15
G8
RF output power gain control 8dB bit (see specification table for logic).
The control voltage at this pin should never exceed 3.3V and a logic
high should be at least 2.7V. This pin should also have an external UHF
bypassing capacitor.
RF IN
VCC1
From Bias
Stages
PD
To RF
Stages
RF OUT
From Bias
Stages
Gxx
VCC2
To RF
Stages
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RF2155
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Application Schematic
915 MHz
Pin
Function
Description
Interface Schematic
16
G16
RF output power gain control 16dB bit (see specification table for
logic). The control voltage at this pin should never exceed 3.3V and a
logic high should be at least 2.7V. This pin should also have an external
UHF bypassing capacitor.
Same as pin 15.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
W=55, L=330 mil
3.9 pF
50
33 pF
RF Out
W=20, L=570 mil
33 pF
33 pF
33 pF
16 dB Ctrl
8 dB Ctrl
V
CC
39
W=20, L=180 mil
33 pF
33 pF
6.8 nH
33 pF
RF In
V
CC
33 pF
Power Down
Board Material: FR-4 (Er=4.7)
h=30 mil
Impedances are critical at pin
2, 7, 11, and 14
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Evaluation Board Schematic
(Download Bill of Materials from www.rfmd.com.)
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
P2-1
R1
39
C4
33 pF
C5
33 pF
C6
1 nF
C13
1
F
C14
1
F
L1
6.8 nH
50
strip
RF IN
J1
C1
33 pF
L=330 mil,
W=55 mil
C10
3.9 pF
C2
33 pF
50
strip
RF OUT
J2
L=570 mil,
W=20 mil
C2
33 pF
P1-1
P2-3
C12 1 nF
C7
33 pF
C8
33 pF
P1-3
C3
33 pF
C9
1 nF
P1-1
P1-3
P1
PD
GND
VB2
1
2
3
P2-1
P2-3
P2
VB1
GND
VCC
1
2
3
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RF2155
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Evaluation Board Layout
Board Size 2.0" x 2.0"
2-185
RF2155
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Pout and Icc vs. Pin, State 10
(915 MHz, Vcc=3.6 V, Vpd=3.0 V)
-5
0
5
10
15
20
25
-20
-15
-10
-5
0
5
10
Pin (dBm)
Pout
(
d
Bm
)
0
50
100
150
200
250
300
Ic
c
(
mA
)
Pout
Icc
Pout and Icc vs. Pin, State 11
(915 MHz, Vcc=3.6 V, Vpd=3.0 V)
5
10
15
20
25
30
-20
-15
-10
-5
0
5
10
Pin (dBm)
Pout
(
d
Bm
)
50
100
150
200
250
300
Ic
c
(
mA
)
Pout
Icc
Pout and Icc vs. Pin, State 01
(915 MHz, Vcc=3.6 V, Vpd=3.0 V)
-10
-5
0
5
10
15
20
-20
-15
-10
-5
0
5
10
Pin (dBm)
Pout
(
d
Bm
)
0
50
100
150
200
250
300
Ic
c
(
mA
)
Pout
Icc
Pout and Icc vs. Pin, State 01
(915 MHz, Vcc=3.6 V, Vpd=3.0 V)
-20
-15
-10
-5
0
5
10
-20
-15
-10
-5
0
5
10
Pin (dBm)
Pout
(
d
Bm
)
0
50
100
150
200
250
300
Ic
c
(
mA
)
Pout
Icc
Pout and Efficiency vs. Vcc, Full Gain
(915 MHz, Pin=0 dBm, Vcc=3.6 V, Vpd=3.0 V)
25
26
27
28
29
30
3.0
3.5
4.0
4.5
5.0
5.5
Vcc (Volts)
Pout
(
d
Bm
)
45.0
48.0
51.0
54.0
57.0
60.0
E
ffic
i
e
n
c
y
(
%)
Pout
Efficiency
Pout vs. Temperature, All Gain Settings
(Pin=0 dBm, Vcc=3.6 V, Vpd=3.0 V)
-5
0
5
10
15
20
25
30
-25
-5
15
35
55
75
95
Temperature (C)
Pout
(
d
Bm
)
Bit1=1;Bit2=1
Bit1=1;Bit2=0
Bit1=0;Bit2=1
Bit1=0;Bit2=0
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Pout vs. Frequency, All Gain Settings
(Pin=0 dBm, Vcc=3.6 V, Vpd=3.0 V)
-5
0
5
10
15
20
25
30
870
880
890
900
910
920
930
940
950
960
Frequency (MHz)
Pout
(
d
Bm
)
Bit1=0;Bit2=0
Bit1=0;Bit2=1
Bit1=1;Bit2=0
Bit1=1;Bit2=1
Icc vs. Frequency, All Gain Settings
(Pin=0 dBm, Vcc=3.6 V, Vpd=3.0 V)
0
50
100
150
200
250
870
880
890
900
910
920
930
940
950
960
Frequency (MHz)
Ic
c
(
mA
)
Bit1=1;Bit2=1
Bit1=1;Bit2=0
Bit1=0;Bit2=1
Bit1=0;Bit2=0
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