Features
Single 15 dB Step
Low Loss, 0.3 dB Typical @ 900 MHz
2.7 to 5.0 Volt Operation
Insertion Loss, Attenuation insensitive to Control
Voltage
Low Cost SOT-25 Plastic Package
Tape and Reel Packaging Available
Description
M/A-COM's AT-267 is a 1 bit, 15 dB step GaAs MMIC
digital attenuator in a low cost SOT-25 5 lead surface
mount plastic package. The AT-267 is ideally suited for
use where high accuracy, very low power consumption and
low intermodulation products are required.
Typical applications include wireless handsets, base
stations, wireless LAN equipment, GPS receivers and any
RF applications with automatic gain/level control circuits.
The AT-267 is fabricated as a monolithic GaAs integrated
circuit using a proven self-aligned gate process. The
process features full chip passivation for performance and
reliability.
Digital Attenuator, 1 Bit, 15 dB Step
DC - 2.0 GHz
A
T
-267
Functional Schematic
RF1
RF2
V1
V2
GND
PIN 5
PIN 1
Positive Control Voltage
Parameter
Absolute Maximum
Maximum Input Power
+21 dBm
Control Voltage V
CTL
-8 V
Operating Temperature
-40 C to +85 C
Storage Temperature
-65 C to +150 C
Absolute Maximum Ratings
1
1. Exceeding any one or a combination of these limits may
cause permanent damage.
Mode
(Control)
V1
V2
Atten
Positive
1
0 0.2 V
+2.5 V to +5 V
+2.5 V to +5 V
0 0.2 V
15 dB
IL
Postitive/
Negative
1,2
-Vc 0.2 V
+Vc
+Vc
-Vc 0.2 V
15 dB
IL
Negative
3
0 0.2 V
-2.5 V to -5 V
-2.5 V to -5 V
0 0.2 V
IL
15 dB
Truth Table
1, 2, 3
1. External DC blocking capacitors are required as noted*
2. |-Vc|+ Vc
8 V
3. If negative control is used, DC blocking capacitors are not
required on RF Ports and Ground.
V 2.00
V2
V1
39 pF
39 pF
39 pF
RF2
GND
RF1
5 4
1 2 3
Digital Attenuator, 1 Bit, 15 dB Step, DC - 2.0 MHz
AT-267
Specifications subject to change without notice.
North America: Tel. (800) 366-2266
Asia/Pacific: Tel.+81-44-844-8296, Fax +81-44-844-8298
Europe: Tel. +44 (1344) 869 595, Fax+44 (1344) 300 020
Visit www.macom.com for additional data sheets and product information.
V 2.00
2
Typical Performance Curves
Electrical Specifications: T
A
= +25 C, V
CTRL
= +2.7 Volts
1
=
=
=
=
Parameter
Test Conditions
Units
Min.
Typ.
Max.
Insertion Loss
1.0 GHz
dB
0.3
0.4
2.0 GHz
dB
0.4
0.5
Attenuation
1.0 GHz
dB
15
15.5
16
2.0 GHz
dB
14
14.5
15
V
SWR
1.0 GHz
1.2:1
2.0 GHz
1.3:1
Input IP
3
1.0 GHz (0 dBm), Attenuator OFF
dBm
40
43
Attenuator ON
40
45
P
1dB
1 GHz, Attenuator OFF
dBm
19
22
Attenuator ON
13
17
Leakage Current
A
10
T
rise
, T
fall
10% to 90% RF, 90% to 10% RF
nS
150
T
on
, T
off
50% Control to 90% RF, Control to 10% RF
nS
150
Transients
In Band
mV
10
1. All measurements in a 50-
system unless otherwise specified. The RF ports must be blocked out side of the package from
ground or any other voltage.
12
13
14
15
16
17
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
FREQUENCY (GHz)
A
tte
nua
ti
on (dB
)
12
13
14
15
16
17
0.0
0.5
1.0
1.5
2.0
2.5
3.0
FREQUENCY (GHz)
A
ttenuation (dB
)
-40 C
+25 C
+85 C
1.0
1.2
1.4
1.6
1.8
2.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
FREQUENCY (GHz)
V
SW
R
15 dB
0 dB
VSWR, 0 and 15 dB States with
Negative Control (-2.7 V) +25 C
Attenuation with Negative Control
(0. 2.7 V)
Attenuation with Positive Control
(0, +2.7 V)
0.0
0.2
0.4
0.6
0.8
1.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
FREQUENCY (GHz)
I
n
serti
o
n
L
o
ss (d
B)
+85 C
+25 C
-40 C
Insertion Loss with Negative Control
(-2.7, 0 V)
Digital Attenuator, 1 Bit, 15 dB Step, DC - 2.0 MHz
AT-267
Specifications subject to change without notice.
North America: Tel. (800) 366-2266
Asia/Pacific: Tel.+81-44-844-8296, Fax +81-44-844-8298
Europe: Tel. +44 (1344) 869 595, Fax+44 (1344) 300 020
Visit www.macom.com for additional data sheets and product information.
V 2.00
Ordering Information
1. If specific reel size is required, consult factory for part
number assignment.
Part Number
Package
AT-267TR
Forward Tape and Reel
1
AT-267TR-3000
3000 Piece Tape and Reel
AT-267SMB
Sample Board
3
SOT-25 Package Outline
1,2
SOT-25 Dimensions
Note: See JEDEC MO-178 VAR AA for additional dimensions
and tolerances.
WZ X Y
D
PIN 5
e1
E1
PIN 5
e
A
A1
b
A2
L
c
E
1. Dimensions do not include mold flash, protrusion or gate
burrs which shall not exceed 0.0098 in (0.25mm) per side.
2. Lead Coplanarity is 0.003 (0.08) max.
DIM
MIN
NOM
MAX
A
-
-
1.45
A1
-
-
0.15
A2
0.90
1.15
1.30
b
0.30
0.50
c
0.08
-
0.22
D
-
2.90 basic
-
e
-
0.95 basic
-
e1
-
1.90 basic
-
E
-
2.80 basic
-
MEASUREMENT (mm)
E1
-
1.60 basic
-
L
0.30
0.60
0.45
0
4
8
-
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