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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
8
7
6
5
RF IN
RF IN
PC
VCC
RF OUT
RF OUT
RF OUT
RF OUT
BIAS
CIRCUIT
PACKAGE BASE
GND
RF2125P
HIGH POWER LINEAR AMPLIFIER
PCS Communication Systems
Digital Communication Systems
DECT Cordless Applications
Commercial and Consumer Systems
Portable Battery-Powered Equipment
The RF2125P 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 PCS phone transmitters and base sta-
tions requiring linear amplification operating between
1500 MHz and 2200 MHz. It will also function as a high
efficiency amplifier for constant envelope applications
such as DECT. The device is packaged in an 8-lead plas-
tic package with a backside ground. The device is self-
contained with the exception of the output matching net-
work and power supply feed line. It produces a typical
output power level of 1 W.
Single 2.7V to 7.5V Supply
1W Output Power
14dB Gain
45% Efficiency
Power Down Mode
1500MHz to 2200MHz Operation
RF2125P
High Power Linear Amplifier
RF2125P PCBA
Fully Assembled Evaluation Board
2
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3.90
0.10
6.00
0.20
4.90
0.10
0.43
0.05
1.27
1.40
0.10
0.05
0.05
-A-
Exposed
Heat Sink
2.70
0.10
0.22
0.03
0.60
0.15
8 MAX
0 MIN
1.70
0.10
Dimensions in mm.
NOTES:
1. Shaded lead is pin 1.
2. Lead coplanarity - 0.10 with respect to datum "A".
Package Style: SOIC-8 Slug
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Absolute Maximum Ratings
Parameter
Rating
Unit
Supply Voltage (V
CC
)
-0.5 to +7.5
V
DC
Power Control Voltage (V
PC
)
-0.5 to +5V
V
DC Supply Current
450
mA
Input RF Power
+20
dBm
Output Load VSWR
20:1
Operating Ambient Temperature
-40 to +85
C
Storage Temperature
-40 to +100
C
Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Overall
T = 25 C, V
CC
=6.0V, V
PC
= 5.0V,
Z
LOAD
= 12
, P
in
= 0dBm, Freq= 1885MHz,
Idle current=180mA
Frequency Range
1500 to 2200
MHz
Maximum Output Power
+28.5
dBm
V
CC
= 3.6V, P
IN
= +17dBm
Maximum Output Power
+29.5
dBm
V
CC
= 4.8V, P
IN
= +17dBm
Maximum Output Power
+29.0
+30
dBm
V
CC
= 6.0V, P
IN
= +17dBm
Total Power Added Efficiency
45
%
Maximum output, V
CC
= 3.6V
Total Power Added Efficiency
45
%
Maximum output, V
CC
= 4.8V
Total Power Added Efficiency
40
45
%
Maximum output, V
CC
= 6.0V
Small-signal Gain
12
14
dB
Second Harmonic
-40
dBc
Third Harmonic
-45
dBc
Fourth Harmonic
-35
dBc
Isolation
15
dB
V
PC
= 0.2V
Input VSWR
1.5:1
With external matching network; see appli-
cation schematic
Two-tone Specification
Average Two-Tone Power
+27
dBm
PEP- 3dB
IM
3
-23
-30
dBc
P
OUT
=+24dBm for each tone
IM
5
-35
dBc
P
OUT
=+24dBm for each tone
IM
7
-45
dBc
P
OUT
=+24dBm for each tone
Power Control
V
PC
1.5
3.3
3.5
V
To obtain 180mA idle current
PC Current
1
mA
V
PC
= 2.0V
2
mA
V
PC
= 3.5V
Power Control "OFF"
0.2
0.5
V
Threshold voltage at device input
Power Supply
Power Supply voltage
2.7 to 7.5
V
Supply Current
200
360
500
mA
P
OUT
= +30dBm, V
CC
= 6.0V
Power Down Current
0.5
10
A
V
PC
= 0.2V
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).
Refer to "Handling of PSOP and PSSOP Products"
on page 16-15 for special handling information.
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Pin
Function
Description
Interface Schematic
1
RF IN
RF input. This input is DC coupled, so an external blocking capacitor is
required if this pin is connected to a DC path. An optimum match to
50
is obtained by providing an external series capacitor of 4.3pF and
then a shunt capacitor of 3.3pF; see the application schematic. Those
values are typical for 1880MHz; other values may be required for other
frequencies.
2
RF IN
Same as pin 1.
3
PC
Power control pin. For obtaining maximum performance the voltage on
this pin can be used to set correct bias level. In a typical application this
is implemented by a feedback loop. The feedback can be based on the
actual supply current of the device, i.e. maintaining a fixed current level,
or it can be based on the RF output power level to maintain a fixed RF
power level (Automatic Level Control loop). A voltage of 0.5V or lower
brings the part into power down state.
4
VCC
Power supply pin for the bias circuits. External low frequency bypass
capacitors should be connected if no other low frequency decoupling is
nearby.
5
RF OUT
RF output and bias for the output stage. The power supply for the out-
put transistor needs to be supplied to this pin. This can be done
through a quarter wave length microstrip line that is RF grounded at the
other end, or through an RF inductor that supports the required DC cur-
rents. Optimum load impedance is achieved by providing a shunt
capacitor of 3.0pF and a series capacitor of 3.9pF; see the application
schematic. Those values are typical for 1880MHz; other values may be
required for other frequencies. Since there are several output pins
available, which are internally connected, one pin can be used for con-
necting the bias, another for connecting a (third) harmonic trap filter,
and the other pins for the RF output.
6
RF OUT
Same as pin 5.
7
RF OUT
Same as pin 5.
8
RF OUT
Same as pin 5.
Pkg
Base
GND
Ground connection. The backside of the package should be connected
to the ground plane through a short path, i.e., vias under the device
may be required.
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Application Schematic
1880MHz Operation
1
2
3
4
8
7
6
5
BIAS
CIRCUIT
PACKAGE BASE
33 nH
2.4 pF
0.01
F
3.9 pF
100 pF
0.1
F
3.6 pF
RF IN
RF OUT
4.3 pF
V
CC
V
PD
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Evaluation Board Schematic
(Download Bill of Materials from www.rfmd.com.)
1
2
3
4
8
7
6
5
BIAS
CIRCUIT
PACKAGE BASE
L1
33 nH
C3
See Chart
C7
1 nF
C4
See Chart
C6
100 pF
C5
1
F
C1
See Chart
P1-3
P1-1
C2
See Chart
C8
1 nF
C9
100 nF
RF OUT
RF IN
J1
J2
Broadband and
Unlicensed PCS
(1910 to 1970 MHz)
Capacitors are ATC type.
The 2.7 pF capacitor is 2.4 pF in parallel with 0.3 pF.
DCS1800
(1710 to 1785 MHz)
Broadband and
Unlicensed PCS
(1850 to 1910 MHz)
DECT
(1880 to 1990 MHz)
APPLICATION
C1 (pF)
C4 (pF)
C3 (pF)
C2 (pF)
3.3
7.5
3.6
3.9
3.0
3.9
2.7
3.6
3.6
4.3
2.4
3.9
3.0
3.9
2.7
3.6
P1-1
P1-3
P1
PC
GND
VCC
1
2
3
2125402 Rev -
50
50
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