Model 3A412S
Rev A
Balun Transformers
50Ω to 12.5Ω Balanced
Description
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.
ELECTRICAL SPECIFICATIONS***
Unbalanced
Port
Balanced
Port
Features:
Return
Loss
Insertion
Loss
Frequency
• 800 – 1000 MHz
Impedance
Ohms
Impedance*
Ohms
• 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
MHz
dB min
15
dB max
0.48
800-1000
869-894
925-960
50
50
50
12.5+j
12.5+j
12.5+j
15
0.35
15
0.40
Amplitude
Balance
Phase
Balance
Power
Handling
Operating
Temp.
ΘJC
• Convenient Package
• Lead Free
dB max
0.40
Degrees max
180± 5.0
180± 5.0
180± 5.0
Watts
250
250
ºC / Watt
3.8
ºC
-55 to +85
-55 to +85
0.40
3.8
0.40
250
3.8
-55 to +85
***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. * 12.5Ω reference to ground
Outline Drawing
Top View (Near-side)
Side View
Bottom View (Far-side)
±.008
±0.20
.075
[1.91
±.004
±0.10
.400
[10.16
]
]
±.004
±0.10
.060
Pin 3
[1.52
]
±.010
±0.25
1.000
[25.40
±.008
±0.20
.070
[1.78
]
]
Pin 2
GND
Pin 3
Pin 2
±.008
±0.20
.050
[1.27
±.004
.030
[0.76
TYP
]
]
±0.10
±.010
.750
±0.25
[19.05
]
±.004
.030
±.008
±0.20
.050
[1.27
±0.10
[0.76
]
]
±.008
.358
±0.20
[9.09
]
Pin 1
Denotes
GND
Pin 1
Array Number
±.004
±0.10
.115
[2.92
]
hes [Millimeters]
Dimensions are in Inc
e
3A412S Mechanical Outlin
USA/Canada:
Toll Free:
Europe:
(315) 432-8909
(800) 544-2414
+44 2392-232392
Available on Tape
and Reel For Pick and
Place Manufacturing.