RF2105L
2
Typical Applications
• 900 MHz ISM Band Applications
• 400 MHz Industrial Radios
• Digital Communication Systems
• Driver Stage for Higher Power Applications
• Commercial and Consumer Systems
• Portable Battery-Powered Equipment
HIGH POWER LINEAR UHF AMPLIFIER
2
POWER AMPLIFIERS
0.025
0.080
Product Description
The RF2105L is a high power, high efficiency linear
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 digital cellular phone transmitters or ISM
applications requiring linear amplification. It is packaged
in a 16-lead ceramic package with a backside ground.
The device is self-contained with the exception of the out-
put matching network and power supply feed line.
0.258
0.242
1
0.075
0.065
0.033
0.017
0.150
0.050
0.258
0.242
R0.008
0.208
sq.
0.192
0.050
0.022
0.018
0.080
Optimum Technology Matching® Applied
Si BJT
Si Bi-CMOS
ü
GaAs HBT
SiGe HBT
Package Style: QLCC-16 Alumina
GaAs MESFET
Si CMOS
Features
• Single 2.7V to 6.5V Supply
• Up to 1.2W CW Output Power
• 33dB Small Signal Gain
• 48% Efficiency
VCC2
1
VCC3 2
VCC1 3
GND 4
PD 5
6
RF IN
16
15
14
13 RF OUT
12 GND
11 RF OUT
10 RF OUT
RF OUT
NC
NC
BIAS
CIRCUIT
• Digitally Controlled Power Down Mode
• Small Package Outline (0.25" x 0.25")
Ordering Information
RF2105L
RF2105L PCBA
High Power Linear UHF Amplifier
Fully Assembled Evaluation Board
7
GND
8
NC
9
NC
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
Rev B3 010720
2-19
RF2105L
Absolute Maximum Ratings
Parameter
Supply Voltage (V
CC
)
Power Down Voltage (V
PD
)
DC Supply Current
Input RF Power
Output Load
Operating Case Temperature
Operating Ambient Temperature
Storage Temperature
Rating
-0.5 to +8.5
-0.5 to +6.5
700
+12
20:1
-40 to +100
-40 to +85
-40 to +150
Unit
V
DC
V
DC
mA
dBm
°C
°C
°C
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).
2
POWER AMPLIFIERS
Parameter
Overall
Frequency Range
Maximum CW Output Power
Specification
Min.
Typ.
Max.
Unit
Condition
T=25 °C, V
CC
=5.8V, V
PD
=5.8V, Z
LOAD
=9Ω,
P
IN
=0dBm, Freq=840MHz
430 to 930
+30.8
MHz
dBm
CW Efficiency at Max Output
DC Current at Max Output
Small-signal Gain
Second Harmonic
Third Harmonic
Fourth Harmonic
Input VSWR
Input Impedance
+29.3
+28.5
+30
+27.8
+27
48
450
33
-23
-36
-35
<2:1
50
dBm
dBm
dBm
dBm
dBm
%
mA
dB
dBc
dBc
dBc
V
CC
=5.8V, V
PD
=5.8V, Z
LOAD
=9Ω
Note that increasing V
CC
above 5.8V does
not result in higher output power; power may
actually decrease.
V
CC
=5.0V, V
PD
=5.0V, Z
LOAD
=9Ω
V
CC
=4.4V, V
PD
=4.4V, Z
LOAD
=9Ω
V
CC
=5.8V, V
PD
=5.8V, Z
LOAD
=12Ω
V
CC
=5.0V, V
PD
=5.0V, Z
LOAD
=12Ω
V
CC
=4.4V, V
PD
=4.4V, Z
LOAD
=12Ω
Without external second harmonic trap
Ω
With external matching network; see appli-
cation schematic
With external matching network; see appli-
cation schematic
PEP-3dB
P
OUT
=+24.0dBm/tone
P
OUT
=+24.0dBm/tone
P
OUT
=+24.0dBm/tone
Two-Tone Specification
Average Two-Tone Power
IM
3
IM
5
IM
7
Two-Tone Current Drain
Two-Tone Power-Added Eff.
+27.0
-30
-32
-40
260
33
-25
-30
350
dBm
dBc
dBc
dBc
mA
%
225
Power Control
Power Down “ON”
Power Down “OFF”
PD Input Current
V
CC
0
3.7
2.7 to 6.5
2
60
80
100
120
V
V
5.0
mA
V
DC
µ
A
mA
mA
mA
mA
Voltage supplied to the input
Voltage supplied to the input
Only in “ON” state
Power Supply
Power Supply Voltage
Total Idle Current Drain
10
V
PD
<0.1V
DC
, V
CC
=6.5V
V
PD
=4.4V
DC
, V
CC
=6.5V
V
PD
=5.0V
DC
, V
CC
=6.5V
V
PD
=5.8V
DC
, V
CC
=6.5V
V
PD
=6.5V
DC
, V
CC
=6.5V
80
165
2-20
Rev B3 010720
RF2105L
Pin
1
Function
VCC2
Description
Positive supply for the second 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 or with a low
value chip inductor (~2.7nH). At lower frequencies, the inductance
value should be larger (longer microstrip line) and V
CC
should be
bypassed with a larger bypass capacitor (see the application schematic
for 430MHz operation). This inductance forms a matching network with
the internal series capacitor between the second and third stages, set-
ting the amplifier’s frequency of maximum gain. An additional 1µF
bypass capacitor in parallel with the UHF bypass capacitor is also rec-
ommended, but placement of this component is not as critical. In most
applications, pins 1, 2, and 3 can share a single 1µF bypass capacitor.
Positive supply for the active bias circuits. This pin can be externally
combined with pin 3 (VCC1) and the pair bypassed with a single UHF
capacitor, placed as close as possible to the package. Additional
bypassing of 1µF is also recommended, but proximity to the package is
not as critical. In most applications, pins 1, 2, and 3 can share a single
1µF bypass capacitor.
Positive supply for the first stage (input) amplifier. This pin can be exter-
nally combined with pin 2 (VCC3) and the pair bypassed with a single
UHF capacitor, placed as close as possible to the package. Additional
bypassing of 1µF is also recommended, but proximity to the package is
not as critical. In most applications, pins 1, 2, and 3 can share a single
1µF bypass capacitor.
Ground connection. For best performance, keep traces physically short
and connect immediately to ground plane. In addition, for specified per-
formance, the package’s backside metal should be soldered to ground
plane.
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
V
CC
(3V to 6.5V), the device will be in full power mode delivering maxi-
mum available gain and output power capability. This pin may also be
used to perform some degree of gain control or power control when set
to voltages between 0V and V
CC
. It is not optimized for this function so
the transfer function is not linear over a wide range as with other
devices specifically designed for analog gain control; however, it may
be usable for coarse adjustment or in some closed loop AGC systems.
This pin should not, in any circumstance, be higher in voltage than V
CC
,
nor should it ever be higher than 6.5V. This pin should also have an
external UHF bypassing capacitor.
Amplifier RF input. This is a 50Ω RF input port to the amplifier. It does
not contain internal DC-blocking and therefore should be externally
DC-blocked before connecting to any device which has DC present or
which contains a DC path to ground. A series UHF capacitor is recom-
mended for the DC-blocking.
Same as pin 4.
Not internally connected.
Not internally connected.
Interface Schematic
2
POWER AMPLIFIERS
2
VCC3
3
VCC1
4
GND
5
PD
6
RF IN
7
8
9
GND
NC
NC
Rev B3 010720
2-21
RF2105L
Pin
10
Function
RF OUT
Description
Amplifier RF output. This is an unmatched collector output of the final
amplifier transistor. It is internally connected to pins 10, 11, 13, and 14
to provide low series inductance and flexibility in output matching. Bias
for the final power amplifier output transistor must also be provided
through two of these four pins. Typically, pins 10 and 11 are connected
to a network that creates a second harmonic trap. For 830MHz opera-
tion, this network is simply a single 2.4pF capacitor from both pins to
ground. This capacitor series resonates with internal bond wires at two
times the operating frequency, effectively shorting out the second har-
monic. Shorting out this harmonic serves to increase the amplifier’s
maximum output power and efficiency, as well as to lower the level of
the second harmonic output. Typically, pins 13 and 14 are externally
connected very close to the package and used as the RF output with a
matching network that presents the optimum load impedance to the PA
for maximum power and efficiency, as well as providing DC-blocking at
the output. An additional network of a bias inductor and parallel resistor
provides DC bias and helps to protect the output from high voltage
swings due to severe load mismatches. Shunt protection diodes are
included to clip peak voltage excursions above ~15V to prevent voltage
breakdown in worst case conditions.
Same as pin 10.
Same as pin 4.
Same as pin 10.
Same as pin 10.
Not internally connected.
Not internally connected.
This contact is the main ground contact for the entire device. Care
should be taken to ensure that this contact is well soldered in order to
prevent performance from being degraded from that indicated in the
specifications.
Interface Schematic
2
POWER AMPLIFIERS
11
12
13
14
15
16
Pkg
Base
RF OUT
GND
RF OUT
RF OUT
NC
NC
GND
2-22
Rev B3 010720
RF2105L
Application Schematic for 430MHz Operation
V
CC
1
µF
10
Ω
100 pF
100 pF
220 nH
180
Ω
15 nH
4.7 nH
1
2
3
16
15
14
13
12
11
10
6
7
8
9
10 pF
33 pF
RF OUT
13 pF
2
POWER AMPLIFIERS
RF OUT
BIAS
CIRCUIT
100 pF
4
1 nF
PD
100 pF
Ground Back of
Package
5
RF IN
100 pF
Application Schematic for 840MHz Operation
V
CC
1
µF
0.01" x 0.20"
(PCB material: FR-4,
Thickness: 0.031")
100 pF
1
2
3
100 pF
4
PD
0/5 V
DC
5
100 pF
6
RF IN
100 pF
7
8
9
Ground Back of
Package
11
10
2.4 pF
16
15
14
13
12
100 pF
47 nH
180
Ω
1.8 nH
6.8 pF
4.7 pF
BIAS
CIRCUIT
Rev B3 010720
2-23
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