RFMD RF2371

RF2371
Preliminary
4
3V LOW NOISE AMPLIFIER
Typical Applications
• GSM Handsets
• IF or RF Buffer Amplifiers
• CDMA Handsets
• Driver Stage for Power Amplifiers
• TDMA Handsets
• Oscillator Loop Amplifiers
Product Description
4
GENERAL PURPOSE
AMPLIFIERS
0.365
TEXT*
The RF2371 is a general purpose, low-cost, high performance low noise amplifier designed for operation from a
2.7V to 4V supply with low current consumption. The
attenuation of the device is controlled when in power
down mode, providing a known gain step. The RF2371 is
available in a small industry-standard SOT23-8 surface
mount package, enabling compact designs which conserve board space. The design features a highly accurate
PTAT (Proportional To Absolute Temperature) biasing
scheme using bandgap cells.
0.15
0.05
1.59
1.61
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
üSi Bi-CMOS
GaAs HBT
GaAs MESFET
SiGe HBT
Si CMOS
Package Style: SOT23-8
Features
• 700MHz to 2000MHz Operation
• 2.7V to 3.6V Single Supply
• +5dBm Input IP3 at 3.0mA
1
8
RF OUT
• 12dB Gain at 1950MHz
GND1 2
7
ISET
• 1.8dB Noise Figure at 1950MHz
6
VCC
• 17dB Gain Step
5
ENABLE
RF IN
GND2 3
Bias Circuits
IPSET 4
Ordering Information
RF2371
RF2371 PCBA
Functional Block Diagram
Rev A2 010205
3V 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
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RF2371
Preliminary
Absolute Maximum Ratings
Parameter
Supply Voltage
Supply Current
Operating Ambient Temperature
Storage Temperature
Parameter
GENERAL PURPOSE
AMPLIFIERS
4
Rating
Unit
4.0
20
-40 to +85
-40 to +150
V
mA
°C
°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
T=27° C, VCC =2.7V, VISELECT =0V,
VENABLE =2.7V
Overall
Frequency Range
700 to 2000
MHz
12.5
1.6
+6
-14
5:1
dB
dB
dBm
dBm
dB
dB
dB
dB
dB
dBm
LNA Performance
Gain
Noise Figure
Input IP3
Input P1dB
Input VSWR
Output VSWR
Off Mode Gain
Gain
Noise Figure
Input IP3
Condition
Freq=1.95GHz
10.5
+4
1.5:1
-5.0
17
1.6
0
At 2.9mA
(Noise match)
VENABLE =0V
Freq=836MHz
Current Control
Internal Current Setting “ON”
External Current Setting “ON”
Current into ISELECT
CMOS Low
CMOS High
1
V
V
µA
Voltage on ISELECT
Voltage on ISELECT
VISELECT =2.7V
1
V
V
µA
Voltage on ENABLE
Voltage on ENABLE
VENABLE =2.7V
5
1
V
mA
µA
VCC =2.7V, Internal current setting
VENABLE =0V
Power Control
Power “ON” Voltage
Power “OFF” Voltage
Current into ENABLE
CMOS High
CMOS Low
Power Supply
Operating Voltage
Operating Current
Leakage Current
4-222
2.7 to 3.6
2.9
Rev A2 010205
RF2371
Preliminary
Function
RF IN
2
GND1
3
4
GND2
IPSET
5
ENABLE
6
7
8
VCC
ISET
RF OUT
Rev A2 010205
Description
Interface Schematic
RF input pin. This pin is not internally DC blocked and requires an
external blocking capacitor.
Ground connection for the LNA. Keep traces physically short and connect immediately to ground plane for best performance.
Ground connection for the bias circuits.
This pin selects the internal current setting when CMOS level “low”, and
the external current setting when this pin is CMOS level “high”.
Power down control. This is a CMOS input. When this pin is CMOS
“high” the device is enabled. When the level is CMOS “low” the device
is shut off and a controlled attenuator is turned on.
Power supply for the bias circuits.
4
This pin sets the current for the device.
RF output pin. Bias for the LNA is provided through this pin, hence it
should be connected to VCC through an inductor.
GENERAL PURPOSE
AMPLIFIERS
Pin
1
4-223
RF2371
Preliminary
Application Information
The RF2371 may be configured to use either the internal current setting or the external current setting. This choice is
made by asserting IPSET, pin 4, to CMOS level “low” for the internal current setting or CMOS level “high” for the external
current setting.
Internal Current Setting
When IPSET is set to CMOS “low”, the internal current settings are chosen. This current draw is typically 2.9mA. In this
mode, the resistorR1 may be removed from the evaluation board schematic and ISET left floating. The condition for optimal IP3 is to use the internal current setting option and leave the ISET pin open (no connect).
GENERAL PURPOSE
AMPLIFIERS
4
External Current Setting
The external current setting is configured by using the series resistor between ISET, pin7, and ground (refer to resistor
R1 in evaluation board schematic). The value of the resistor may be changed to permit various operating currents up to a
maximum allowable current of 20mA. The table below gives approximate minimum R1 values to allow the 20mA maximum current draw at various operating voltages.
Note: When the internal current setting was selected, the part tested drew 4.4mA, which is higher than typical
(2.9mA). Thus values of R1 given vary from part to part.
VCC (V)
Resistor R1 (Ω)
Current Draw (mA)
2.7
2.4k
20.1
3.0
2.7k
20.1
3.3
3.0k
20.0
3.6
3.3k
19.8
4-224
Rev A2 010205
RF2371
Preliminary
Application Schematic
1.95GHz
VCC
3.3 nH
22 nF
RF IN
1
10 nF
1.5 pF
RF OUT
8
1 kΩ
2
7
3
6
VCC
4
Bias Circuits
4
ENABLE
5
GENERAL PURPOSE
AMPLIFIERS
IPSET
Application Schematic
836MHz
VCC
18 nH
22 nF
RF IN
82 nH
1
8
2
7
3
6
1 pF
RF OUT
1 kΩ
VCC
Bias Circuits
IPSET
Rev A2 010205
4
5
ENABLE
4-225
RF2371
Preliminary
Evaluation Board Schematic
(Download Bill of Materials from www.rfmd.com.)
VCC
L1
3.9 nH
C1
22 nF
J2
LNA INPUT
L2
10 nH
GENERAL PURPOSE
AMPLIFIERS
4
1
8
2
7
3
6
C2
1.5 pF
R1
1 kΩ
J1
LNA OUTPU
VCC
Bias Circuits
IPSET
4
ENABLE
5
2371400-
IPSET
VCC
ENABLE
ENVCC+
2.6 V
C3
1 nF
C4
1 uF
+
C5
22 nF
VCC+
2.7 V-
P1
1
VCC
2
ENABLE
3
IPSET
GND
4
CON4
4-226
Rev A2 010205
RF2371
Preliminary
Evaluation Board Layout
Board Size 0.833” x 1.009”
Board Thickness 0.031”, Board Material FR-4
GENERAL PURPOSE
AMPLIFIERS
4
Rev A2 010205
4-227
RF2371
Preliminary
GENERAL PURPOSE
AMPLIFIERS
4
4-228
Rev A2 010205