Page 1
Preliminary
RF2368
4
Typical Applications
• DCS Handsets
• PCS Handsets
Product Description
The RF2368 is a DCS/PCS low noise amplifier with
bypass switch designed for use as a front-end for
DCS1800/PCS1900 applications.The LNA is a two-stage
amplifier with bypass switch. This amplifier has low noise
figure and high linearity in both high gain and bypass/low
gain mode.
DCS/PCS 2.7V LOW NOISE AMPLIFIER
• General Purpose Amplification
• Commercial and Consumer Systems
1.44
1.04
0.15
0.05
1.59
1.61
2.80
3.00
2.60
3.00
*WhenPin1isinupper
left, text readsdownward
(as shown).
0.365
TEXT*
0.650
3°MAX
0°MIN
4
AMPLIFIERS
GENERAL PURPOSE
0.127
Optimum Technology Matching® Applied
Si BJT GaAs MESFETGaAs HBT
Si Bi-CMOS
BIAS
GND
IN
GND1
ü
SiGe HBT
1
2
3
4
Control Logic
Si CMOS
SELECT
8
OUT
7
GND2
6
VCC
5
0.35
0.55
Package Style: SOT 8 Lead
Features
• Low Noise and High I ntercept Point
• Power Down Control
•SwitchableGain
Ordering Information
RF2368 DCS/PCS 2.7V Low Noise Amplifier
RF2368 PCBA Fully Assembled Evaluation Board
Functional Block Diagram
Rev A0 010503
RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro,NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
4-199
Page 2
RF2368
Absolute Maximum Ratings
Parameter Rating Unit
Supply Voltage -0.5 to +6.0 V
Input RF Level +10 dBm
Storage Temperature -40 to +150 °C
DC
Preliminary
Caution! ESD sensitive device.
RF Micro Devices believes thefurnished information iscorrect andaccurate
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).
4
GENERAL PURPOSE
Parameter
Min. Typ. Max.
Specification
Unit Condition
Operating Range
Overall Frequency Range 1800 2000 MHz
Supply Voltage (V
Power Down Voltage (V
Logic Control Voltage Level 0 2.86 V SELECT
Operating Ambient Temperature -40 +85 °C
Input Impedance 50 Ω
Output Impedance 50 Ω
) 2.7 2.78 2.86 V V
CC
) 2.7 2.78 2.86 V BIAS
BIAS
1850 MHz Performance
AMPLIFIERS
High Gain Mode
Gain 17 18 19 dB
Gain Variation Over
Tempera ture Range
Gain Variation Over
Frequency Band
Current Consumption 9.0 9.5 mA I
Noise Figure 1.6 1.7 dB
Reverse Isolation 15 20 dB
Input IP3 0.0 +1.0 dBm
Input P1dB -13 -10 dB
+
0.5 dB
0.5 dB
+
1850 MHz Performance
Bypass Mode
Gain -4.5 dB
Gain Reductio n 21 22.5 24 dBc
Power Down Current 10 µA
Input IP3 12 15.0 dBm
Input P1dB +5 +8 dB
1960 MHz Performance -
High Gain Mode
Gain 15.5 16.5 17.5 dB
Gain Variation Over
Tempera ture Range
Gain Variation Over
Frequency Band
Current Consumption 9.0 9.5 mA I
Noise Figure 1.6 1.7 dB
Reverse Isolation 15 20 dB
Input IP3 +1 +2 dBm
Input P1dB -13 -10 dB
+
0.5 dB
0.5 dB
+
1960 MHz Performance -
Bypass Mode
Gain -5 dB
Gain Reductio n 20 21.5 23 dBc
Power Down Current 10 µA
Input IP3 14.0 17.0 dBm
Input P1dB +5 +8 dB
CC1,VCC2
T= 25°C,RF=1850MHz, VCC=BIAS=2.78V,
SELECT=0V, Z
CC+IBIAS
T= 25°C, RF=1850MHz, VCC=2.78V,
SELECT=2.7 V, Z
T= 25°C,RF=1960MHz, VCC=BIAS=2.78V,
SELECT=0V, Z
CC+IBIAS
T= 25°C, RF=1960MHz, VCC=2.78V,
SELECT=2.7 V, Z
IN=ZO
IN=ZO
IN=ZO
IN=ZO
=50Ω
=50Ω
=50Ω
=50Ω
4-200
Rev A0 010503
Page 3
Preliminary
RF2368
Pin Function Description Interface Schematic
1BIAS
BIAS is set to the supply voltage at high gain mode. For bypass mode
see “Application Notes”.
BIAS
2GND
3IN
DCS1800/PCS1900 R F input pin.
To Bias
Circuit
VCC1
4GND1
5VCC
6GND2
7OUT
8 SELECT
LNA1 emittance ind uctance. Total inductance is comprised of
package+bondwire+L2 on PCB.
Open collector for first stage LNA of DCS1800/PCS1900. It must be
biased to V
LNA2 emittance ind uctance. Total inductance is comprised of
package+bondwire+L4 on PCB.
DCS1800 Amplifier Output pin. This pin is an open-collector output. It
must be biased to V
is typically matched to 50Ω with a shunt bias/matching inductor and
series blocking/matching capacitor.Refer to application schematics.
This pin selects high gain.
Select <
Select >
through a choke or matching inductor.
CC
through a choke or matching inductor. This pin
CC
0.8V, high gain.
1.8V, low gain.
RF IN
SELECT
VCC1
GND1
RF OUT
GND2
4
GND1
AMPLIFIERS
GENERAL PURPOSE
Rev A0 010503
4-201
Page 4
4
RF2368
Preliminary
Applicat ion Notes
Bypass Mode Configurations
The RF2368 may be placed into either high gain or bypass mode via the GAIN SELECT pin (pin 8). The high gain state
is selected by asserting the GAIN SELECT pin to a voltage level of less than 0.8V. For Bypass operation, there are two
possiblemethods for placing the RF2368 into thislowgain state. The table below shows the two possible Bypass configurations.
Bypass Mode Possibilities
Gain Select BIAS (V) VCC1 and VCC2 (V) Current (mA)
2.7 0 2.78 1.4
2.7 2.7 2.78 2.2
For both Bypass configurations, the GAIN SELECT pin must be placed at a level greater than or equal to 1.8V. The difference between the Bypass possibilities is determined by the specific application's ability to change the voltage of the
BIAS pin (pin 1) independently of the V
0 V when in Bypass mode is shown by the decreased current draw when in this Bypass configuration.
BIAS Pin Resistor
AMPLIFIERS
The BIAS pin (pin1) of the RF2368 should be maintained at 2.7V to 2.86V for proper high gain operation. This voltage
GENERAL PURPOSE
range ensures the correct bias current will be present at the BIAS pin of the device. However, an external series resistor
may be used to allow various operating voltages at this pin (see R1 of the evaluation board schematic). The required
value for this resistor may be roughly calculated by using the operatinginput voltage to the BIAS pin, the desired voltage
at the device, and the typical current consumption for the BIAS pin, along withOhm's law.
supply voltage. The advantage of the ability to assert the power down pin to
CC
For example, assume the design will supply 5.0V to the BIAS pin of the device, but the biasing circuitry inter nal to the
RF2368 requires 2.78V typical, and the BIAS current is known to typically be 0.25mA, then the required value for R1
would be found as follows.
5.0V 2.78V–
------------------------------- -
0.25mA
8.88kΩ=
4-202
Rev A0 010503
Page 5
Preliminary
RF2368
Application Schematic
BIAS
RFIN
0 Ω
8.2 nH
0.1 uF
33 nF
2.7 nH
SELECT
0.1 µF
1
2
3
4
Control Logic
8
7
1.5 nH
6
5
3.9 nH 10 kΩ
10 nF
100 pF
VCC1
VCC2
100 pF
10 nF
3.9 nH 10 kΩ
0.8 pF
RF OUT
4
AMPLIFIERS
GENERAL PURPOSE
Rev A0 010503
4-203
Page 6
RF2368
Preliminary
Evaluation Board Schematic - PCS/DCS
(Download Bill of Materials from www.rfmd.com.)
4
GENERAL PURPOSE
AMPLIFIERS
P1-1 BIAS
P1-3 SELECT
BIAS
J1
RF IN
50 Ωµstrip
P1
1
2
3
HDR_3
0 Ω
8.2 nH
R1
P2
1
P2-1 VCC2
GND
P2-3 VCC1
C1
0.1 uF
L1
C2
33 nF
L2
2.7 nH
2
3
HDR_3
1
2
3
4
2368310,rev. 2
GND
Control Logic
SELECT
C8
0.1 µF
8
7
6
5
L3
3.9 nHR210 kΩ
VCC1
L4
1.5 nH
C4
100 pF
C3
10 nF
VCC2
C7
10 nF
C6
100 pF
L5
3.9 nHR310 kΩ
C5
0.8 pF
50 Ωµstrip
J2
RF OUT
4-204
Rev A0 010503
Page 7
Preliminary
RF2368
Evaluation Board Layout
Board Size 1” x 1”
Board Thickness 0.032”, Board Material FR-4
4
AMPLIFIERS
GENERAL PURPOSE
Rev A0 010503
4-205
Page 8
RF2368
Preliminary
4
GENERAL PURPOSE
AMPLIFIERS
High Gain Mode Input Impedance (S11)
8
.
1.0-1.0
0
6
.
0
4
.
0
2
.
0
0
0.2
0.4
2
.
0
-
4
.
0
-
6
.
0
-
0.6
.
0
-
8
0.8
2.0 GHz
1.0
2.0
1.5 GHz
2
3.0 GHz
3.0
0
0
.
.
3
5.0
4.0
1.0 GHz
0
.
.
2
-
Bypass Mode Input Impedance (S11)
8
.
1.0-1.0
0
6
.
0
4
.
0
3.5 GHz
2
.
0
0
.
2
3
Swp Max
4GHz
0
0
.
4
0
.
5
.
0
1
10.0
0
.
0
0
.
5
0
.
4
-
3
-
Swp Min
0.01GHz
Swp Max
4GHz
0
.
0
.
4
0
.
5
0
1
High Gain Mode Output Impedance (S22)
8
.
1.0-1.0
0
6
.
0
4
.
0
2
.
0
0
0
0.2
0.4
0.6
1
-
2
.
0
-
-
4
.
0
-
6
.
0
-
8
.
0
-
1.0 GHz
1.0
0.8
2.0
100 MHz
2.0 GHz
Swp Max
0
.
2
3.0
0
.
2
4GHz
0
.
3
0
.
4
0
.
5
0
.
0
1
10.0
5.0
4.0
0
.
0
1
-
0
.
5
-
0
.
4
-
0
.
3
-
-
Swp Min
0.01GHz
Bypass Mode Output Impedance (S22)
8
.
1.0-1.0
0
6
.
0
4
.
0
2
.
0
0
.
Swp Max
0
.
3
2.0 GHz
4
4GHz
0
.
.
5
1
0
0
.
0
0
.
2
0
0.2
0.4
6
.
0
-
1.5 GHz
3.0 GHz
2
.
0
-
4
.
0
-
1.0
0.6
0.8
8
.
0
-
2.0
2.5 GHz
3.0
2.0 GHz
1.0 GHz
10.0
5.0
4.0
0
.
0
1
-
0
.
5
-
0
.
4
-
0
.
3
-
0
.
2
-
Swp Min
0.01GHz
0
0.2
0.4
2
.
0
-
4
.
0
-
6
.
0
-
1.0
0.6
0.8
8
.
0
-
2.0
3.0 GHz
3.0
10.0
5.0
4.0
0
.
2
-
3.7 GHz
0
.
0
.
3
-
Swp Min
0.01GHz
0
.
0
.
5
4
-
1.0 GHz
0
1
-
-
S-Parameter Conditions:
All plots shown were takenat VCC=2.78V and Ambient Temperature=25°C.
Note:
All S11 and S22 plots shown were taken from an RF2368 while on a 2368310 evaluation board. The data was captured without the external input or output tuning components in place, and the reference points at the RF IN and RF OUT pins of the device.
4-206
Rev A0 010503
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