Datasheet RF2421, RF2421PCBA Datasheet (RF Micro Devices)

RF2421

9

Typical Applications

• P ower Control in Communication Systems

• CMOS Compatible Programmable
Attenuator

Product Description

The RF2421 is a monolithic switched attenuator. The
device is built using a Gallium Arsenide process technol­ogy and has a single step attenuation of 10dB. The input
and output of the device has a low VSWR 50Ω match.
The RF output can drive up to +16dBm. This unit is
intended for use in systems that require RF power control
by digital means. No negative supply voltages are
required, and the current consumption is less than 5
when the attenuator is off.

µA

10dB SWITCHED ATTENUA TOR

• Commercial and Consumer Systems

• Portable Battery-Powered Equipment

0.008

0.004

0.018

0.014

0.196

0.189

8° MAX

0° MIN

0.034

0.016

0.157

0.150

0.244

0.229

0.050

Dimensions in mm

NOTES:

1. Shaded lead is Pin 1.

2. All dimensions are excluding
mold flash.

3. Lead coplanarity -

0.005 with respect to datum "A".

0.009

0.007

0.068

0.053

-A-

9

Optimum Technology Matching® Applied

Si BJT GaAs MESFETGaAs HBT
Si Bi-CMOS

NC

RF IN

GND

RF OUT

SiGe HBT

1

2

3

4

!

Si CMOS

8

7

6

5

NC

G10

VDD

NC

Functional Block Diagram

Package Style: SOIC-8

Features

• Single 2.7V to 6V Supply

• 10dB Single Step Attenuation

• 1 dB Insertion Loss

• 1-bit Digitally Controlled Attenuation

• Digitally Controlled Power Down Mode

• 500MHz to 3000 MHz Operation

Ordering Information

RF2421 10dB Switched Attenuator
RF2421 PCBA Fully Assembled Evaluation Board

RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA

Tel [phone]

Fax [phone]

http://www.rfmd.com

SWITCHES

A T TENTUA TORS AND

Rev A6 001102

9-15

RF2421

Absolute Maximum Ratings

Parameter Rating Unit

Supply Voltage -0.5 to +6.0 V
Control Voltage -0.5 to +6.0 V

Input RF Power +20 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 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).

9

Parameter

Min. Typ. Max.

Overall

Frequency Range 500 to 3000 MHz
Insertion Loss 1.0 1.5 dB V

Insertion Loss 9.5 10 10.5 dB V
Gain Flatness 0.25 dB In any 50MHz band

Specification

Unit Condition

T=25°C, VDD=5.0V, Freq=915MHz

=0V

G10

DC

G10=VDD

Input

Input Impedance 50 Ω
Input VSWR 1.3:1
Input 1dB Compression +17 dBm

Attenuation Control

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

Current 0.4 0.5 mA Into control line, V
Response Time <10 ns

DD

V Voltage supplied to input

=5V

G10

DC

Output

IM

3

Harmonic Output -40 dBc With 0dBm output in each of 2 tones, attenu­Output Impedance 50 Ω

Output VSWR 1.3:1

Power Supply

SWITCHES

Voltage 5 V Specifications

A T TENTUA TORS AND

Current 0.5 mA Attenuation “ON”

-60 dBc With 0dBm output in each of 2 tones, attenu­ation “OFF”.

ation “OFF”.

2.7 5 6.0 V Operating Limits

5 µA Attenuation “OFF”

9-16

Rev A6 001102

RF2421

Pin Function Description Interface Schematic

1NC
2RF IN

Not internally co nnected. This pin can be grounded.
RF Input. This pin is not DC blocked, and an external blocking capacitor

is recommended. The value depends on the frequency used.

RF IN RF OUT

3GND
4RF OUT
5NC

6VDD
7G10

8NC

Ground connection. Keep trace physically short and connect immedi­ately to the ground plane for best performance.

RF Output. This pin is not DC blocked, and an external blocking capac­itor is recommended. The value depends on the frequency used.

Not internally co nnected. This pin can be grounded.
Power supply pin. An external RF bypass capacitor is recommended.
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.

Not internally co nnected. This pin can be grounded.

Evaluation Board Schemati c

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

P1

P1-1

P1-3

1

VDD

2

GND

ATTN

3

See pin 2.

G10

9

SWITCHES

A T TENTUA TORS AND

Rev A6 001102

RF IN

J1

RF OUT

J2

50

50

Ω µ

Ω µ

strip

strip

C3

100 pF

C4

100 pF

2421400 Rev A

1

2

3

4

8

7

6

5

P1-3

P1-1

C1

100 pFC2100 nF

9-17

RF2421

Evaluation Board Layout

Board Thickness 0.031”; Board Material FR-4

9

SWITCHES

A T TENTUA TORS AND

9-18

Rev A6 001102