Alpha Industries, Inc. [781] 935-5150
Fax [978] 241-7906 Email sales@alphaind.com www.alphaind.com
1
Specifications subject to change without notice. 9/01A
GaAs 4 Bit Digital Attenuator
2, 4, 8, 16 dB Bits DC2 GHz
Features
Low DC Power Consumption
Attenuation in 2 dB Steps to 30 dB with
High Accuracy
14 Lead Hermetic Surface Mount Package
Capable of Meeting MIL-STD
Requirements
6
AT002D4-31
Description
The AT002D4-31 is an MMIC FET digital attenuator
consisting of four monolithic attenuators with an LSB of
2 dB and a total attenuation of 30 dB with all attenuators
connected. This attenuator is recommended for fast
response, low power consumption AGC circuits. Typical
applications include AGC circuits for radar processing,
instrumentation and levelers in RF equipment.
Parameter
1
Frequency
5
Min.
Typ.
Max.
Unit
Insertion Loss
2
DC0.5 GHz
2.6
3.0
dB
DC1.0 GHz
3.3
3.9
dB
DC2.0 GHz
5.0
5.8
dB
Attenuation Range
3
DC1.0 GHz
28
30
dB
DC2.0 GHz
26
30
dB
Attenuation Accuracy Per Bit
DC1.0 GHz
(0.4 + 5% of Attenuation
Setting in dB)
DC2.0 GHz
(0.5 + 5% of Attenuation
Setting in dB)
VSWR
DC0.5 GHz
1.3:1
1.5:1
DC2.0 GHz
1.6:1
1.8:1
Electrical Specifications at 25C
1. All measurements made in a 50
system, unless otherwise specified.
2. Insertion loss changes by 0.003 dB/C.
3. Attenuation value referenced above insertion loss.
Parameter
Condition
Frequency
Min.
Typ.
Max.
Unit
Switching Characteristics
Rise, Fall (10/90% or 90/10% RF)
7
ns
On, Off (50% CTL to 90/10% RF)
14
ns
Video Feedthru
4
20
mV
Input Power for 1 dB Compression
0.52 GHz
27
dBm
Intermodulation Intercept Point (IP3)
For Two-tone Input Power 13 dBm
0.52 GHz
43
dBm
0.0010.5 GHz
32
dBm
Control Voltages
V
Low
= 0 to -0.2 V @ 20 A Max.
V
High
= -5 V @ 50 A to -9 V @ 200 A Max.
Operating Characteristics at 25C
-31
0.340 (8.64 mm)
0.315 (8.00 mm)
ORIENTATION
MARK
0.270 (6.86 mm) MAX.
0.395 (10.03 mm)
MAX.
0.500 (12.70 mm) MAX.
0.006 (0.15 mm)
0.004 (0.10 mm)
0.070 (1.78 mm)
0.040 (1.02 mm)
0.075 (1.91 mm) MAX.
0.038 (0.97 mm)
0.025 (0.64 mm)
0.050 (1.27 mm)
0.017 (0.43 mm)
4. Video feedthru measured with 1 ns risetime pulse and 500 MHz bandwidth.
5. DC = 300 kHz.
6. See Quality/Reliability section.
GaAs 4 Bit Digital Attenuator 2, 4, 8, 16 dB Bits DC2 GHz
AT002D4-31
2
Alpha Industries, Inc. [781] 935-5150
Fax [978] 241-7906 Email sales@alphaind.com www.alphaind.com
Specifications subject to change without notice. 9/01A
Insertion Loss vs. Frequency
Frequency (GHz)
Inser
tion Loss (dB)
+85C
-55C
3.5
3.0
2.5
2.0
1.5
1.0
DC
0.2
0.4
0.6
0.8
1.0
2.0
2.5
2.2
1.9
1.6
1.3
1.0
VSWR vs. Frequency (All States)
DC
0.2
0.4
0.6
0.8
1.0
3.0
Frequency (GHz)
Frequency (GHz)
Atten
uation (dB)
30
Attenuation vs. Frequency by BIT
DC
0.2
0.4
0.6
0.8
1.0
2.0
20
15
10
5
0
30 dB 1.0
16 dB 0.6
8 dB 0.4
4 dB 0.4
2 dB 0.3
Typical Performance Data
Pin Out
V
7
V
8
GND
J
1
GND
GND
GND
J
2
V
6
V
5
V
4
V
3
V
2
V
1
Characteristic
Value
RF Input Power (RF In)
2 W > 500 MHz 0/-8 V
0.5 W @ 50 MHz 0/-8 V
Control Voltage (V
C
)
+0.2 V, -10 V
Operating Temperature (T
OP
)
-55C to +125C
Storage Temperature (T
ST
)
-65C to +150C
Thermal Resistance (
JC
)
25C/W
Absolute Maximum Ratings
Truth Table
V
1
V
2
V
3
V
4
V
5
V
6
V
7
V
8
Condition
2 dB
4 dB
8 dB
16 dB
J
1
J
2
-5
0
-5
0
0
-5
-5
0
Insertion Loss
0
-5
-5
0
0
-5
-5
0
2 dB State
-5
0
0
-5
0
-5
-5
0
4 dB State
-5
0
-5
0
-5
0
-5
0
8 dB State
-5
0
-5
0
0
-5
0
-5
16 dB State
0
-5
0
-5
-5
0
0
-5
30 dB Max. Atten.
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