ALPHA AA280-25 Datasheet

Alpha Industries, Inc. [781] 935-5150 • Fax [617] 824-4579 • Email [e-mail] • www.alphaind.com 1

Specifications subject to change without notice. 11/00A

GaAs IC 5 Bit Digital Attenuator

0.5 dB LSB DC–2 GHz

Features

■ Attenuation 0.5 dB Steps to 15.5 dB
with High Accuracy

■ Low DC Power Consumption

■ Low Cost SOIC-16 Plastic Package

SOIC-16

AA280-25

(Previously AD280-25)*

0.158 (4.00 mm)

0.150 (3.80 mm)

0.068

(1.73 mm) MAX.

0.244 (6.20 mm)

0.228 (5.80 mm)

0.049 (1.24 mm)

0.016 (0.41 mm)

0.016 MAX.
(0.41 mm)

x 45˚

CHAMFER

0.020 (0.51 mm)

0.013 (0.33 mm)

0.050

(1.27 mm) BSC

PIN 16

PIN 1

PIN 1

INDICATOR

0.394 (10.00 mm)

0.386 (9.80 mm)

0.010 (0.25 mm)

0.004 (0.10 mm)

0.0098 (0.25 mm)

0.0075 (0.19 mm)

8˚ MAX.

Description

The AD280-25 is a 5 bit, GaAs IC FET digital attenuator
in a low cost SOIC-16 package. This attenuator has an
LSB of 0.5 dB and a total attenuation of 15.5 dB.

The AD280-25 is particularly suited where high
attenuation accuracy, low insertion loss and low
intermodulation products are required. Typical applications
include cellular radio, wireless data, wireless local loop and
other gain level control circuits.

Parameter

1

Condition Frequency

2

Min. Typ. Max. Unit

Insertion Loss

3

DC–0.5 GHz 1.1 1.3 dB
DC–1.0 GHz 1.4 1.7 dB
DC–2.0 GHz 1.7 2.0 dB

Attenuation Range 15.5 dB

Attenuation Accuracy

3

DC–1.0 GHz ± (0.2 + 3% of

Attenuation Setting in dB) dB

DC–2.0 GHz ± (0.4 + 3% of

Attenuation Setting in dB) dB

VSWR (I/O

)4

DC–2.0 GHz 1.4:1 1.8:1

Switching Characteristics

5

Rise, Fall (10/90% or 90%/10% RF) 15 nS
On, Off (50% CTL to 90%/10% RF) 25 nS
Video Feedthru 25 mV

Input Power for 1 dB Compression 0.5–2.0 GHz +24 +29 dBm

0.05 GHz +17 +22 dBm

Intermodulation Intercept Point (IP3) For Two-tone Input Power +5 dBm 0.5–2.0 GHz +44 +50 dBm

0.05 GHz +35 +40 dBm

Control Voltages V

Low

= 0 to 0.2 V @ 20 µA Max.

V

High

= -5 V @ 300 µA Max.

Electrical Specifications at -40°C to +85°C (0, -5 V)

1. All measurements made in a 50 Ω system, unless otherwise specified.

2. DC = 300 kHz.

3. Attenuation referenced to insertion loss.

4. Input/Output

5. Video feedthru measured with 1 ns risetime pulse and 500 MHz bandwidth.

*Due to conflict with another company’s product numbering system, Alpha’s attenuator products starting with the letters “AD” are being changed to “AA”.

GaAs IC 5 Bit Digital Attenuator 0.5 dB LSB DC–2 GHz AA280-25

2 Alpha Industries, Inc. [781] 935-5150 • Fax [617] 824-4579 • Email [e-mail] • www.alphaind.com

Specifications subject to change without notice. 11/00A

Insertion Loss (dB)

Frequency (GHz)

Insertion Loss vs. Frequency

0 0.5 1.0 1.5 2.0

-2.00

-1.75

-1.50

-1.25

-1.00

-0.75

-0.50

+25˚C

+85˚C

-40˚C

IP3 (dBm)

Attenuation (dB)

IP3 vs. Attenuation and Temperature

46

48

50

52

54

56

58

0123456789

10 11 12 13 14 15

+25˚C

+85˚C

-40˚C

VSWR

Frequency (GHz)

VSWR vs. Frequency (25˚C)

0 0.5 1.0 1.5 2.0

1.0

1.1

1.2

1.3

1.4

1.5

Ins. Loss

0.5 dB

1 dB

2 dB

4 dB

8 dB

15.5 dB

VSWR

Frequency (GHz)

VSWR vs. Frequency (85˚C)

0 0.5 1.0 1.5 2.0

1.0

1.1

1.2

1.3

1.4

1.5

Ins. Loss

0.5 dB

1 dB

2 dB

4 dB

8 dB15.5 dB

VSWR

Frequency (GHz)

VSWR vs. Frequency (-40˚C)

0 0.5 1.0 1.5 2.0

1.0

1.1

1.2

1.3

1.4

1.5

Ins. Loss

0.5 dB

1 dB

2 dB

4 dB

8 dB

15.5 dB

Typical Performance Data (0, -5 V)

Compression Point vs. Attenuation,
Voltage, and Temperature

Attenuation Control

Input Power @ 1 dB Compression

State Voltage (V)+25°C (dBm) +85°C (dBm) -40°C (dBm)

Ins. Loss -5 28.30 28.10 29.10

0.5 dB -5 28.50 28.30 29.40

1.0 dB -5 28.70 28.70 29.60

2.0 dB -5 28.40 28.30 29.10

4.0 dB -5 32.90 32.90 33.90

8.0 dB -5 36.80 36.80 36.80

15.5 dB -5 32.70 32.10 32.80