Datasheet RF2420, RF2420PCBA Datasheet (RF Micro Devices)

RF2420

9

Typical Applications

• Power Control in Communication Systems

• CMOS Compatible Programmable
Attenuators

Product Description

The RF2420 is a multistage monolithic programmable
attenuator. The device is built using an advanced Gallium
Arsenide process technology and has an attenuation pro­grammability over a 44dB range in 2 dB steps. The atten­uation is set by five bits of digital data. The input and
output of the device have a low VSWR 50Ω match. This
unit is intended for use in systems that require RF trans­mit power control by digital means. Typical applications
are in dual mode IS-54/55 compatible cellular transceiv­ers and TETRA systems. No negative supply voltages
are required.

PROGRAMMABLE ATTENUATOR

• Commercial and Consumer Systems

• Portable Battery-Powered Equipment

-A-

0.008

0.004

0.393

0.386

8° MAX

0° MIN

0.157

0.150

0.244

0.229

0.034

0.016

0.009

0.007

0.018

0.014

0.050

0.068

0.053

NOTES:

1. Shaded lead isPin 1.

2. All dimensions are excluding
mold flash.

3. Lead coplanarity - 0.005 with
respectto datum "A".

9

Optimum Technology Matching® Applied

Si BJT GaAs MESFETGaAs HBT
Si Bi-CMOS

RF IN

VDD

VDD

VDD

VDD

VDD

VDD

VDD

1

2

3

4

5

6

7

8

SiGe HBT

2dB

4dB

8dB

10 dB

20 dB

ü

Si CMOS

16

G2

15

G4

14

G8

13

GND

12

GND

11

G10

10

G20

9

RF OUT

Functional Block Diagram

Package Style: SOIC-16

Features

• 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

Ordering Information

RF2420 ProgrammableAttenuator
RF2420 PCBA Fully Assembled Evaluation Board

RF Micro Devices, Inc.
7628 ThorndikeRoad
Greensboro,NC 27409, USA

Tel [phone]

Fax [phone]

http://www.rfmd.com

SWITCHES

ATTENTUATORSAND

Rev A6 010720

9-9

RF2420

Absolute Maximum Ratings

Parameter Rating Unit

Supply Voltage -0.5 to +7.0 V
RF Input Power +17 dBm

Operating Ambient Temperature -40 to +85 ° C
Storage Temperature -40 to +150 °C

DC

Caution! ESD sensitive device.

RF Micro Devices believes the furnished informationis correct 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 useof the described product(s).

9

Parameter

Min. Typ. Max.

Overall

Frequency Range DC to 950 MHz Tuning of bypass capacitors is required for

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

Specification

50 MHz At maximum attenuation

Unit Condition

T=25°C and 5V at 420MHz

shifting the center frequency. See the evalu­ation board schematic for details.

Input

Input Impedance 50 Ω
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 C ontrol

Attenuation “ON” Voltage 2.5 V
Attenuation “OFF” Voltage 0.3 V Voltage Supplied to input

Current 0.4 1. 0 mA Into each control line
Response Time <10 ns

DD

V Voltage Supplied to input

Output

SWITCHES

IM3 -30 dBc With 0dBm output in each of 2 tones

ATTENTUATORSAND

Harmonic Output -40 dBc
Output Impedance 50 Ω
Output VSWR 1.2:1 1.5:1

Power Supply

Voltage 5 V Specifications

3 to 6 V Operating Lim its

Current 4 8 mA Operating

0.4 0.75 mA Power Down

9-10

Rev A6 010720

RF2420

Pin Function Description Interface Schematic

1RFIN

RF Input. This pin is not DC-blocked, and an external blocking capaci­tor is required. The value depends on the frequency used. The DC
value on this pin is approximately equal to VDD.

RF IN

2VDD

3VDD
4VDD
5VDD
6VDD
7VDD
8VDD
9RFOUT

10 G20

11 G10

12 GND
13 GND
14 G8

15 G4

16 G2

VDD supply connection. Bypassing is critical: To achieve maximum
attenuation range the magnitude of the impedance a t the operation fre ­quency,as seen from the package pins, needs to be less than 0.5Ω.
The DC source to the pin m ay be a logic dr iver gate to implement a
Power Down function.

Same as pin 2.
Same as pin 2.
Same as pin 2.
Same as pin 2.
Same as pin 2.
Same as pin 2.
RF Output. Same as pin 1. Pin 1 and 9 are interchangeable.

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.

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.

Ground.
Ground.
Control pin fo r the 8dB attenuator. This pin has an internal pull-down

resistor, so when the pin is not connected the attenuator will be turned
off.

Control pin fo r the 4dB attenuator. This pin has an internal pull-down
resistor, so when the pin is not connected the attenuator will be turned
off.

Control pin fo r the 2dB attenuator. This pin has an internal pull-down
resistor, so when the pin is not connected the attenuator will be turned
off.

Gxx

Same as pin 10.

Same as pin 10.

Same as pin 10.

Same as pin 10.

RF OUT

9

SWITCHES

ATTENTUATORSAND

Rev A6 010720

9-11

RF2420

Evaluation Board Schema t ic

(Download Bill of Materials from www.rfmd.com.)

9

SWITCHES

P2

P2-1 G2
P2-2 G4
P2-3 G8
P2-4 G10
P2-5 G20

1
2
3
4
5

NC

6

NC

7

NC

8
9

NC

10

Note:
Series resonant at F0; place C2
midway between pin 2 and pin 8

J1

SMA

GND

NC

P1-3 VDD

RF IN

50 Ωµstrip

P1-3

P1

1

GND

2
3

P2-1

C1

100 pF

C2

120 pF

C3

10 µF

1

2

3

4

5

6

7

8

2420400B

2dB

4dB

8dB

10 dB

20 dB

16

15

14

13

12

11

10

9

C4

100 pF

C9

100 pF

C8

100 pF

C7

100 pF

C6

100 pF

C5

100 pF

50 Ωµstrip

RF OUT

P2-2

P2-3

P2-4

P2-5

J2

SMA

ATTENTUATORSAND

9-12

Rev A6 010720

Evaluation Board Layout

Board Size 2.020” x 2.020”

Board Thickness 0.031”, Board Material FR-4

RF2420

9

SWITCHES

ATTENTUATORSAND

Rev A6 010720

9-13

RF2420

9

SWITCHES

ATTENTUATORSAND

9-14

Rev A6 010720