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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
5
6
7
8
16
15
14
13
12
11
10
9
RF IN
VDD
VDD
VDD
VDD
VDD
VDD
VDD
G2
G4
G8
GND
GND
G10
G20
RF OUT
2 dB
4 dB
8 dB
10 dB
20 dB
RF2420
PROGRAMMABLE ATTENUATOR
Power Control in Communication Systems
CMOS Compatible Programmable
Attenuators
Commercial and Consumer Systems
Portable Battery-Powered Equipment
The RF2420 is a multistage monolithic programmable
attenuator. The device is built using an advanced Gallium
Arsenide process technology and has an attenuation pro-
grammability over a 44dB range in 2dB steps. The atten-
uation is set by five bits of digital data. The input and
output of the device have a low VSWR 50
match. This
unit is intended for use in systems that require RF trans-
mit power control by digital means. Typical applications
are in dual mode IS-54/55 compatible cellular transceiv-
ers and TETRA systems. No negative supply voltages
are required.
Single 3V to 6V Supply
0dB to 44dB Attenuation Range
4dB Insertion Loss
5-bit Digitally Controlled Attenuation
Digitally Controlled Power Down Mode
DC to 950MHz Frequency Range
RF2420
Programmable Attenuator
RF2420 PCBA
Fully Assembled Evaluation Board
9
Rev A6 010720
NOTES:
1. Shaded lead is Pin 1.
2. All dimensions are excluding
mold flash.
3. Lead coplanarity - 0.005 with
respect to datum "A".
0.050
0.018
0.014
0.157
0.150
0.393
0.386
0.244
0.229
8 MAX
0 MIN
0.034
0.016
0.009
0.007
0.068
0.053
0.008
0.004
-A-
Package Style: SOIC-16
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RF2420
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Absolute Maximum Ratings
Parameter
Rating
Unit
Supply Voltage
-0.5 to +7.0
V
DC
RF Input Power
+17
dBm
Operating Ambient Temperature
-40 to +85
C
Storage Temperature
-40 to +150
C
Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Overall
T = 25C and 5V at 420MHz
Frequency Range
DC to 950
MHz
Tuning of bypass capacitors is required for
shifting the center frequency. See the evalu-
ation board schematic for details.
Insertion Loss
4
6
dB
Attenuation Range
0 to 44
dB
Gain Flatness
3
dB
In any 50MHz band, at max attenuation
3dB Bandwidth
500
MHz
At 26dB attenuation
50
MHz
At maximum attenuation
Input
Input Impedance
50
Input VSWR
1.2:1
1.5:1
Input 1dB Compression
+13
+15
dBm
Attenuation
Attenuation Settings
2, 4, 8, 10, 20
dB
CMOS Level, 5 bits
Accuracy
0.5
dB
2dB step
1.0
dB
4dB through 20dB steps
Attenuation Control
Attenuation "ON" Voltage
2.5
V
DD
V
Voltage Supplied to input
Attenuation "OFF" Voltage
0.3
V
Voltage Supplied to input
Current
0.4
1.0
mA
Into each control line
Response Time
<10
ns
Output
IM3
-30
dBc
With 0dBm output in each of 2 tones
Harmonic Output
-40
dBc
Output Impedance
50
Output VSWR
1.2:1
1.5:1
Power Supply
Voltage
5
V
Specifications
3 to 6
V
Operating Limits
Current
4
8
mA
Operating
0.4
0.75
mA
Power Down
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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Pin
Function
Description
Interface Schematic
1
RF IN
RF Input. This pin is not DC-blocked, and an external blocking capaci-
tor is required. The value depends on the frequency used. The DC
value on this pin is approximately equal to VDD.
2
VDD
VDD supply connection. Bypassing is critical: To achieve maximum
attenuation range the magnitude of the impedance at the operation fre-
quency, as seen from the package pins, needs to be less than 0.5
.
The DC source to the pin may be a logic driver gate to implement a
Power Down function.
3
VDD
Same as pin 2.
4
VDD
Same as pin 2.
5
VDD
Same as pin 2.
6
VDD
Same as pin 2.
7
VDD
Same as pin 2.
8
VDD
Same as pin 2.
9
RF OUT
RF Output. Same as pin 1. Pin 1 and 9 are interchangeable.
10
G20
Control pin for the 20dB attenuator. This pin has an internal pull-down
resistor, so when the pin is not connected the attenuator will be turned
off.
11
G10
Control pin for the 10dB attenuator. This pin has an internal pull-down
resistor, so when the pin is not connected the attenuator will be turned
off.
Same as pin 10.
12
GND
Ground.
13
GND
Ground.
14
G8
Control pin for the 8dB attenuator. This pin has an internal pull-down
resistor, so when the pin is not connected the attenuator will be turned
off.
Same as pin 10.
15
G4
Control pin for the 4dB attenuator. This pin has an internal pull-down
resistor, so when the pin is not connected the attenuator will be turned
off.
Same as pin 10.
16
G2
Control pin for the 2dB attenuator. This pin has an internal pull-down
resistor, so when the pin is not connected the attenuator will be turned
off.
Same as pin 10.
RF IN
RF OUT
Gxx
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Evaluation Board Schematic
(Download Bill of Materials from www.rfmd.com.)
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
2 dB
4 dB
8 dB
10 dB
20 dB
P2-1
C4
100 pF
C8
100 pF
C7
100 pF
C5
100 pF
C6
100 pF
C9
100 pF
2420400B
C1
100 pF
P1-3
C3
10
F
C2
120 pF
Note:
Series resonant at F0; place C2
midway between pin 2 and pin 8
50
strip
J1
SMA
RF IN
50
strip
J2
SMA
RF OUT
P2-3
P2-5
P2-2
P2-4
NC
P1-3
VDD
GND
P1
1
2
3
NC
NC
NC
NC
P2-1
G2
P2-2
G4
P2-3
G8
P2-4
G10
P2-5
G20
GND
1
2
3
4
5
6
7
8
9
10
P2
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RF2420
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Evaluation Board Layout
Board Size 2.020" x 2.020"
Board Thickness 0.031", Board Material FR-4
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