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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
6
5
4
VCC
GND
RF IN
RF OUT
GND
GC
ATT
ATT
RF2381
PCS/CELLULAR TDMA/CDMA/W-CDMA
LINEAR VARIABLE GAIN AMPLIFIER
CDMA PCS/Cellular Handsets
TDMA PCS/Cellular Handsets
W-CDMA Handsets
The RF2381 is a linear variable gain amplifier suitable for
use in TDMA and CDMA systems in the cellular or PCS
band and for W-CDMA systems. The features of this
device include linear gain control, high gain, and high lin-
earity. The IC is manufactured on an advanced Gallium
Arsenide Heterojunction Bipolar Transistor (GaAs HBT)
process and is featured in an industry-standard miniature
6-lead plastic SOT package.
50dB Linear Gain Control Range
22dB Maximum Gain
Single 2.7V to 3.3V Supply
35mA Supply Current
High Linearity
RF2381
PCS/Cellular TDMA/CDMA/W-CDMA Linear Vari-
able Gain Amplifier
RF2381 PCBA
Fully Assembled Evaluation Board
4
Rev A1 010511
.90
.70
.10 MAX.
1.30
1.00
3.10
2.70
.37 MIN.
3.00
2.60
1.90
.25
.10
.50
.35
1.80
1.40
9
T
EXT
*
*When Pin 1 is in
upper left, text
reads downward
(as shown).
All dimensions in mm.
1
Package Style: SOT23-6
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Absolute Maximum Ratings
Parameter
Rating
Unit
Supply Voltage
0 to +5.0
V
DC
DC Current
100
mA
Operating Ambient Temperature
-30 to +85
C
Storage Temperature
-40 to +150
C
Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Overall
V
CC
= 2.8V, V
GC
= 2.0V, T= 25C
Usable Frequency Range
800 to 2100
MHz
Linear Gain Control Range
50
dB
Gain Control Slope
70
dB/V
Input VSWR
1.5:1
2.5:1
Over entire gain control range
Output VSWR
1.5:1
2.5:1
Over entire gain control range
Output IP3
+23
+26
dBm
Noise Figure
9
dB
Maximum gain
TDMA
V
CC
= 2.8V, V
GC
= 2.0V, T= 25C
Operating Frequency
1880
MHz
Maximum Small Signal Gain
18
20
22
dB
Maximum Average Output Power
+8
dBm
TDMA modulation; ACP<-32dBc
Maximum Average Input Power
-9
-8
dBm
TDMA modulation; for any V
GC
that gives
P
OUT
<+8dBm, ACP <-32dBc, ALT<-52dBc
Adjacent Channel Power
-33
-32
dBc
TDMA modulation; P
OUT
<+8dBm and
P
IN
<-11dBm, at all V
GC
.
-61
-52
dBc
TDMA modulation; P
OUT
<+8dBm and
P
IN
<-11dBm, at all V
GC
.
CDMA
V
CC
= 2.8V, V
GC
= 2.0V, T= 25C
Operating Frequency
1880
MHz
Maximum Small Signal Gain
18
20
22
dB
Maximum Average Output Power
+6
dBm
CDMA modulation; V
CC
= 3.0V, maximum
gain setting, ACP <-52dBc.
Maximum Average Input Power
-13
dBm
CDMA modulation; for any V
GC
that gives
P
OUT
<+6dBm, ACP <-52dBc
Adjacent Channel Power
-53
dBc
CDMA modulation; V
CC
= 3.0V.
P
OUT
<+6dBm and P
IN
<-13dBm, at all V
GC
.
W-CDMA
V
CC
= 2.8V, V
GC
= 2.0V, T= 25C
Operating Frequency
1920 to 1980
MHz
Small Signal Gain
17.5
19.5
22
dB
Maximum Linear Output Power
+5
dBm
W-CDMA ACP<-46dBc
Adjacent Channel Power
-46
dBc
W-CDMA modulation; P
OUT
<+5dBm and
P
IN
<-12dBm
-43
dBc
W-CDMA modulation; Over entire gain con-
trol range, P
IN
< -17dBm
-43
dBc
W-CDMA modulation; V
GC
=1.0V,
P
IN
<-14dBm
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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Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Power Supply
T= 25C
Supply Voltage
2.8
V
Specifications
2.7 to 3.3
V
Operating range
Gain Control Voltage (V
GC
)
0 to 2.2
V
Supply Current
35
mA
V
CC
= 2.8V, V
GC
= 2.2V
50
mA
V
CC
= 3.3V, V
GC
= 2.2V
21
mA
V
CC
= 2.8V, V
GC
= 0.4V
V
GC
Current
-2.0
+2.4
mA
V
GC
= 0.4V to 2.2V
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Application Schematic
1850MHz to 1910MHz
Pin
Function
Description
Interface Schematic
1
RF OUT
RF output pin. This pin is DC-coupled and requires V
CC
through a bias
inductor sized accordingly to provide a high pass transformation with a
series capacitor.
2
GND
Ground connection. For best performance, keep traces physically short
and connect immediately to ground plane.
3
GC
Analog gain control pin. This pin controls the gain of the IC. Minimum
gain occurs at V
GC
< 0.4V and maximum gain is achieved with
V
GC
= 2.0V. 50dB of linear gain control with little variation of input P
1dB
is available.
4
RF IN
RF input pin. This pin is DC-coupled.
5
GND
Ground connection. For best performance, keep traces physically short
and connect immediately to ground plane.
6
VCC
Power supply. This pin should be connected to a regulated supply and
requires a series inductor and bypass capacitor. Voltage is supplied
through this pin to the first stage collector; this voltage also controls the
bias. Gain may be tuned by adjusting the value of the feed inductor.
RF IN
4
5
6
3
2
1
Note orientation of
package in this schematic.
1 pF
GC
2.7 nH
33 nF
VCC
RF OUT
2.7 nH*
33 nF
VCC
ATT
ATT
100 pF
33 pF
*For W-CDMA, use 2.2 nH
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Evaluation Board Schematic
Note orientation of
package in this schematic.
C8
1 pF
L2
2.7 nH
C3
33 nF
L3
2.7 nH
C4
33 nF
VCC
50
strip
J2
RF OUT
C6
33 nF
C7
1
F
50
strip
J1
RF IN
VCC
GC
C1
100 pF
P1
1
2
3
4
5
GND
P1-3
P1-4
VCC
GND
P1-1
GC
4
5
6
3
2
1
ATT
ATT
C2
33 pF
C5
33 pF
2381401-
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Evaluation Board Layout
Board Size 2.0" x 2.0"
Board Thickness 0.028", Board Material FR-4, Multi-Layer
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TDMA ACP versus P
OUT
over Temperature,
P
IN
=-9 dBm, f=1880 MHz, V
CC
=2.8 V
-37
-35
-33
-31
-29
-27
-25
-50
-40
-30
-20
-10
0
10
20
P
OUT
(dBm)
ACP
(
dBc)
+25C
-30C
+85C
TDMA AltCP versus P
OUT
over Temperature,
P
IN
=-9 dBm, f=1880 MHz, V
CC
=2.8 V
-70
-65
-60
-55
-50
-45
-40
-50
-40
-30
-20
-10
0
10
20
P
OUT
(dBm)
AltCP
(
dBc)
+25C
-30C
+85C
Note: Below P
OUT
=-35 dBm,
test equipment noise floor inhibits
accurate AltCP measurement
Supply Current versus Gain-Control Voltage over
Temperature,
P
IN
=-9 dBm, F=1880 MHz, V
CC
=2.8 V
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
0.00
0.50
1.00
1.50
2.00
2.50
V
GC
(V)
I
CC
(mA)
Icc,mA, +25C
Icc,mA, -30C
Icc,mA, +85C
Gain versus Gain-Control Voltage over Temperature,
P
IN
=-9 dBm, F-1880 MHz, V
CC
=2.8 V
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
10.00
20.00
30.00
0.00
0.50
1.00
1.50
2.00
2.50
V
GC
(V)
Gain
(dB)
+25C
-30C
+85C
W-CDMA ACPR versus V
GC
at Various Output Powers
-60
-55
-50
-45
-40
-35
0.8
1
1.2
1.4
1.6
1.8
2
V
GC
(V)
ACPR
(dBc)
Pout=+2dBm
Pout=+3dBm
Pout=+4dBm
Pout=+6dBm
Pout=+8dBm
Note: Below V
GC
=~1.1V,
test equipment noise floor inhibits
accurate ACP measurement
NF versus VGC
(RF Freq. 1950MHz, V
CC
=2.8V, V
GC
=2.0 to 0.2V)
0.0
10.0
20.0
30.0
40.0
50.0
60.0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
V
GC
(V)
NF
(dB)
NF [dB]
4-50
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Output Power versus Input Power
(RF Freq. 1950MHz, V
CC
=2.8V, V
GC
=2.0V)
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
-14.0
-12.0
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
Input Power (dBm)
Output
Power
(
dBm)
Pout [dBm]
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