MACOM AT-255, AT-255TR Datasheet

3Volt Voltage Variable Attenuator
25 dB, DC - 2 .5 GHz

AT-255

Features

• Single Voltage Control 0 to -3 Volts

• 25 dB Attenuation Range at 0.9 GHz

• Low DC Power Consumption

• Low Cost SOT-25 Plastic Package

• Tape and Reel Packaging Available

Description

M/A-COM’s AT-255 is a GaAs MMIC voltage variable
absorptive attenuator in a low cost SOT-25 surface mount
plastic package. The AT-255 is ideally suited for use where
variable attenuation fine tuning and very low power
consumption are required.

Typical applications include radio, cellular, GPS equipment and
automatic gain/level control circuits.

The AT-255 is fabricated using a mature 1-micron GaAs
MESFET process. The process features full chip passivation for
increased performance and reliability.

Ordering Information

Part Number Package

AT-255 SOT-25 Plastic
AT-255TR Forward Tape and Reel

1. Reference Application Note M513 for reel size information.

1

SOT-25

Note: 1. Leads Coplanarity should be 0.003 (0.08) max.

DIM

INCHES MI LLIMETERS

MIN MAX MIN MAX

A .106 .122 2.70 3.10
B .100 .118 2.54 3.00
C
D .063 REF. 1.60 REF.
E .032 .043 .80 1.10
F .014 .020 .35 .50
G .003
H .000 .006 .00 .15

J .018 REF. .45 REF



.051





.08

1.30



1

Electrical Specifications: TA = +25°C

====

Parameter Test Conditions Units Min. Typ. Max.

Insertion Loss DC - 2.0 GHz dB 3.6 4.2
Attenuation DC - 1.0 GHz dB 23 25

1.0 - 2.0 GHz dB 18 20
Flatness (Peak-to-Peak) DC - 1.0 GHz dB ±7 ±10

1.0 - 2.0 GHz dB ±5 ±8
VSWR DC - 2.0 GHz 3:1

T

, T

rise

fall

Ton, T

off

Transients

1. All measurements at 1 GHz in a 50Ω system unless otherwise specified. Insertion Loss varies 0.003 dB/°C.

Specifications subject to change without notice.

 North America: Tel. [phone], Fax [phone]
 Asia/Pacific: Tel.[phone], Fax [phone]
 Europe: Tel. [phone], Fax+ 44 (1 34 4) 30 0 020

Visit www.macom . com for ad di tional data sheets and pr o d uct i nf orm ation.

10% to 90% RF, 90% to 10% RF nS 10
50% Control to 90% RF, Control to 10% RF nS 20
In-band mV 10

V 4.0

1

INPUT IP3 vs CONTROL VOLTAGE

Q

0

0

3 Volt Voltage Variable Attenuator, 25 dB, DC - 2.5 GHz

AT-255

Absolute Maximum Ratings

1

Parameter Absolute Maximum

Maximum Input Power +21 dBm
Control Voltage V

C

-8V, +0.5V
Operating Temperature -40°C to +85°C
Storage Temperature -65°C to +150°C

1. Exceeding any one or a combination of these limits may cause

permanent damage.

Typical Performance Curves

Relative Attenuation vs. Control Voltage Insertion Loss vs. Frequency

0

-5

-10

-15

-20

-25

ATTENUATION (dB)

-30

-35

-3 -2 -1 0

CONTROL VOLTAGE (VOLTS)

2.5GHz

50MHz

Functional Schematic

5

1

GND

RF

1. VCC = 0 VDC to -3 V

-1

-2

-3

ATTENUATION(dB)

-4
01234

@ 50 µA max.

DC

FREQUENCY(GHz)

1

GNDVc

4

2

3

RF

Maximum Relative Attenuation vs. Frequency

0

-5

-10

-15

-20

-25

ATTENUATION(dB)

-30

-35

00.511.522.53

FREQUENCY (GHz)

Input IP3 vs. Control Voltage

45
40
35
30
25
20

IP3 (dBm)

15
10

5
0

-3 -2 -1 0

Specifications subject to change without notice.

 North America: Tel. [phone], Fax [phone]
 Asia/Pacific: Tel.[phone], Fax [phone]
 Europe: Tel. [phone], Fax+ 44 (1 34 4) 30 0 020

500 MHz

50MHz

CONTROL VOLTAGE (VOLTS)

Return Loss vs. Control @ 900 MHz

-5

-10

-15

-20

RETURN LOSS (dB)

-25

-3 -2 -1 0

Input P1dB vs. Control Voltage

30
25

50MHz

20

500MHz

15
10

5
0

COMPRESSION POINT (dBm)

-3 -2 -1 0

CONTROL VOLTAGE (VOLTS)

CONTROL VOLTAGE (VOLTS)

V 4.0

2

Visit www.macom . com for ad di tional data sheets and pr o d uct i nf orm ation.