RFMD RF2368PCBA

RF2368
Preliminary
4
DCS/PCS 2.7V LOW NOISE AMPLIFIER
Typical Applications
• DCS Handsets
• General Purpose Amplification
• PCS Handsets
• Commercial and Consumer Systems
0.365
TEXT*
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.
4
0.15
0.05
1.59
1.61
GENERAL PURPOSE
AMPLIFIERS
Product Description
2.80
3.00
0.650
2.60
3.00
1.44
1.04
*When Pin 1 is in upper
left, text reads downward
(as shown).
0.127
3°MAX
0°MIN
0.35
0.55
Optimum Technology Matching® Applied
Si BJT
Si Bi-CMOS
ü
GaAs HBT
GaAs MESFET
SiGe HBT
Si CMOS
Package Style: SOT 8 Lead
Features
• Low Noise and High Intercept Point
• Power Down Control
• Switchable Gain
BIAS 1
GND 2
IN 3
GND1 4
Control Logic
8 SELECT
7 OUT
6 GND2
5 VCC
Ordering Information
RF2368
RF2368 PCBA
Functional Block Diagram
Rev A0 010503
DCS/PCS 2.7V Low Noise Amplifier
Fully Assembled Evaluation Board
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
RF2368
Preliminary
Absolute Maximum Ratings
Parameter
Supply Voltage
Input RF Level
Storage Temperature
Parameter
Rating
Unit
-0.5 to +6.0
+10
-40 to +150
VDC
dBm
°C
Specification
Min.
Typ.
Max.
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).
Unit
Condition
Operating Range
GENERAL PURPOSE
AMPLIFIERS
4
Overall Frequency Range
Supply Voltage (VCC)
Power Down Voltage (VBIAS)
Logic Control Voltage Level
Operating Ambient Temperature
Input Impedance
Output Impedance
1800
2.7
2.7
0
-40
2.78
2.78
2000
2.86
2.86
2.86
+85
50
50
MHz
V
V
V
°C
Ω
Ω
1850MHz Performance
High Gain Mode
Gain
Gain Variation Over
Temperature Range
Gain Variation Over
Frequency Band
Current Consumption
Noise Figure
Reverse Isolation
Input IP3
Input P1dB
T = 25°C, RF=1850MHz, VCC =BIAS=2.78V,
SELECT=0V, ZIN =ZO =50Ω
17
15
0.0
-13
18
9.0
1.6
20
+1.0
-10
19
+0.5
dB
dB
+0.5
dB
9.5
1.7
mA
dB
dB
dBm
dB
1850MHz Performance
Bypass Mode
Gain
Gain Reduction
Power Down Current
Input IP3
Input P1dB
21
-4.5
22.5
12
+5
15.0
+8
24
10
dB
dBc
µA
dBm
dB
T = 25°C, RF=1960MHz, VCC =BIAS=2.78V,
SELECT=0V, ZIN =ZO =50Ω
15.5
15
+1
-13
16.5
9.0
1.6
20
+2
-10
17.5
+0.5
dB
dB
+0.5
dB
9.5
1.7
mA
dB
dB
dBm
dB
1960MHz Performance Bypass Mode
Gain
Gain Reduction
Power Down Current
Input IP3
Input P1dB
4-200
ICC +IBIAS
T = 25°C, RF=1850MHz, VCC =2.78V,
SELECT=2.7V, ZIN =ZO =50Ω
1960MHz Performance High Gain Mode
Gain
Gain Variation Over
Temperature Range
Gain Variation Over
Frequency Band
Current Consumption
Noise Figure
Reverse Isolation
Input IP3
Input P1dB
VCC1, VCC2
BIAS
SELECT
ICC +IBIAS
T = 25°C, RF=1960MHz, VCC =2.78V,
SELECT=2.7V, ZIN =ZO =50Ω
20
-5
21.5
14.0
+5
17.0
+8
23
10
dB
dBc
µA
dBm
dB
Rev A0 010503
RF2368
Preliminary
Pin
1
Function
BIAS
2
3
GND
IN
Description
Interface Schematic
BIAS is set to the supply voltage at high gain mode. For bypass mode
see “Application Notes”.
DCS1800/PCS1900 RF input pin.
BIAS
To Bias
Circuit
VCC1
4
GENERAL PURPOSE
AMPLIFIERS
RF IN
GND1
4
GND1
5
VCC
LNA1 emittance inductance. Total inductance is comprised of
package+bondwire+L2 on PCB.
Open collector for first stage LNA of DCS1800/PCS1900. It must be
biased to VCC through a choke or matching inductor.
VCC1
GND1
6
GND2
7
OUT
LNA2 emittance inductance. 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 VCC through a choke or matching inductor. This pin
is typically matched to 50Ω with a shunt bias/matching inductor and
series blocking/matching capacitor. Refer to application schematics.
RF OUT
GND2
8
SELECT
Rev A0 010503
This pin selects high gain.
Select <0.8V, high gain.
Select >1.8V, low gain.
SELECT
4-201
RF2368
Preliminary
Application 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
possible methods for placing the RF2368 into this low gain state. The table below shows the two possible Bypass configurations.
Bypass Mode Possibilities
GENERAL PURPOSE
AMPLIFIERS
4
Gain Select
2.7
2.7
BIAS (V)
0
2.7
VCC1 and VCC2 (V)
2.78
2.78
Current (mA)
1.4
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 VCC supply voltage. The advantage of the ability to assert the power down pin to
0V when in Bypass mode is shown by the decreased current draw when in this Bypass configuration.
BIAS Pin Resistor
The BIAS pin (pin1) of the RF2368 should be maintained at 2.7V to 2.86V for proper high gain operation. This voltage
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 operating input voltage to the BIAS pin, the desired voltage
at the device, and the typical current consumption for the BIAS pin, along with Ohm's law.
For example, assume the design will supply 5.0V to the BIAS pin of the device, but the biasing circuitry internal 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
-------------------------------- = 8.88k Ω
0.25mA
4-202
Rev A0 010503
RF2368
Preliminary
Application Schematic
SELECT
VCC2
100 pF
10 nF
0.1 µF
0Ω
1
0.1 uF
2
Control Logic
8
3.9 nH
8.2 nH
0.8 pF
4
RF OUT
7
33 nF
RFIN
10 kΩ
1.5 nH
3
6
4
5
GENERAL PURPOSE
AMPLIFIERS
BIAS
2.7 nH
3.9 nH
10 kΩ
10 nF
100 pF
VCC1
Rev A0 010503
4-203
RF2368
Preliminary
Evaluation Board Schematic - PCS/DCS
(Download Bill of Materials from www.rfmd.com.)
P1
P1-1
P1-3
P2
1
BIAS
2
GND
3
SELECT
P2-1
P2-3
HDR_3
GENERAL PURPOSE
AMPLIFIERS
4
VCC2
2
GND
3
VCC1
SELECT
VCC2
C7
10 nF
C6
100 pF
HDR_3
C8
0.1 µF
R1
0Ω
BIAS
1
C1
0.1 uF
J1
RF IN
1
Control Logic
8
2
7
3
6
4
5
L5
3.9 nH
R3
10 kΩ
C5
0.8 pF
50 Ω µstrip
J2
RF OUT
50 Ω µstrip
L1
8.2 nH
C2
33 nF
L2
2.7 nH
2368310, rev. 2
L4
1.5 nH
L3
3.9 nH
R2
10 kΩ
C4
100 pF
C3
10 nF
VCC1
4-204
Rev A0 010503
RF2368
Preliminary
Evaluation Board Layout
Board Size 1” x 1”
Board Thickness 0.032”, Board Material FR-4
GENERAL PURPOSE
AMPLIFIERS
4
Rev A0 010503
4-205
RF2368
Preliminary
0.8
2.
0
0
3.
4.0
5.0
1.0 GHz
10.0
2.0 GHz
10.0
4.0
5.0
3.0
2.0
1.0
0.8
0.6
0.4
0
10.0
0.2
10.0
4.0
5.0
3.0
2.0
1.0
0.8
0.6
0.4
0.2
0.6
2.
0
0.2
0
Swp Max
4GHz
0.2
0
4.
5.0
4
1.0
1.0
0.8
0.
4
0
3.
3.0 GHz
2.0 GHz
-10.0
-3
.0
-1.0
1.0
0.8
2.
0
2.
0
0.6
Swp Max
4GHz
0.
4
4.0
5.0
0.2
4.0
5.0
0
3.
0.2
4.0
5.0
3.0
2.0
1.0
0.8
0.6
0.4
-1.0
.0
-2
.4
-0
-0.
6
.0
-2
Swp Min
0.01GHz
3.7 GHz
3.0 GHz
-0.8
-1.0
-0.8
0.2
0
4.0
5.0
3.0
2.0
1.0
0.8
0.6
0.4
-0.
6
-3
.0
2.5 GHz
-0.2
-3
.0
3.0 GHz
-4.
0
-5.0
1.0 GHz
.4
-0
1.0 GHz
-4.
0
-5.0
0.2
10.0
-10.0
2.0 GHz
1.5 GHz
-0.2
2.0 GHz 10.0
-10.0
0
10.0
10.0
0.
4
0
3.
3.5 GHz
Swp Min
0.01GHz
Bypass Mode Output Impedance (S22)
Swp Max
4GHz
0.6
0.8
1.0
Bypass Mode Input Impedance (S11)
-0.8
-0.
6
Swp Min
0.01GHz
.0
-2
.4
-0
.0
-2
-1.0
-0.8
-0
.6
-
4
0.
-3
.0
-4
.0
-5.
0
1.5 GHz
100 MHz
-0.2
-4.
0
-5.0
1.0 GHz
2
-0.
-10.0
GENERAL PURPOSE
AMPLIFIERS
High Gain Mode Output Impedance (S22)
Swp Max
4GHz
0.
4
6
0.
High Gain Mode Input Impedance (S11)
Swp Min
0.01GHz
S-Parameter Conditions:
All plots shown were taken at 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