Model 3A412S
Balun Transformers
50 to 12.5 Balanced
The 3A412S is a low profile balanced to unbalanced transformer designed for push-
pull amplifiers in an easy to use surface mount package for AMPS and GSM. These
compact Xinger
®
surface mount baluns are ideal for high volume manufacturing
and are more reliable and repeatable than traditional baluns. The 3A412S has an
unbalanced port impedance of 50Ω and balanced port impedances of 12.5Ω to
ground with a 25Ω balance between outputs. This eases the matching of the push-
pull amplifier’s power transistors, which have low impedance levels. The output
ports have equal amplitude (-3dB) with 180 degree phase differential. The Xinger
®
balun is a result of years of research and development culminating with a solution
so unique, a patent is pending on the design approach. The 3A412S is available on
tape and reel for pick and place high volume manufacturing.
Rev A
Description
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Features:
ELECTRICAL SPECIFICATIONS***
Frequency
MHz
800 – 1000 MHz
180° Transformer
°
50 Ohm to 2 x 12.5+j Ohm
Low Insertion Loss
High Power
Even Order Suppression
Input to Output DC Isolation
Surface Mountable
Tape & Reel
Convenient Package
Lead Free
Unbalanced
Port
Impedance
Ohms
Balanced
Port
Impedance*
Ohms
Return
Loss
dB min
Insertion
Loss
dB max
800-1000
869-894
925-960
Amplitude
Balance
dB max
50
50
50
Phase
Balance
Degrees max
12.5+j
12.5+j
12.5+j
Power
Handling
Watts
15
15
15
Θ
JC
ºC / Watt
0.48
0.35
0.40
Operating
Temp.
ºC
0.40
0.40
0.40
180± 5.0
180± 5.0
180± 5.0
250
250
250
3.8
3.8
3.8
-55 to +85
-55 to +85
-55 to +85
Outline Drawing
Top View (Near-side)
1.000
±.010
[25.40
±0.25
]
***Specification based on performance of unit properly installed on microstrip printed circuit
boards with 50
Ω
nominal impedance. Specifications subject to change without notice.
**Insertion Loss excludes reflected power. * 12.5
Ω
reference to ground
Side View
[1.91
±0.20
]
Pin 3
.075
±.008
Bottom View (Far-side)
.060
±.004
[1.52
±0.10
]
Pin 3
.400
±.004
[10.16
±0.10
]
.070
±.008
[1.78
±0.20
]
Pin 2
.030
±.004
TYP
[0.76
±0.10
]
.050
±.008
[1.27
±0.20
]
Pin 2
.750
±.010
[19.05
±0.25
]
GND
Pin 1
Denotes
Array Number
.050
±.008
[1.27
±0.20
]
.030
±.004
[0.76
±0.10
]
GND
Pin 1
.358
±.008
[9.09
±0.20
]
.115
±.004
[2.92
±0.10
]
Dimensions are in Inches [Millimeters]
3A412S Mechanical Outline
Available on Tape
and Reel For Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
(315) 432-8909
(800) 544-2414
+44 2392-232392