Available on Tape
and Reel For Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
(315) 432-8909
(800) 544-2414
+44 2392-232392
Model 3A412S
Rev A
Balun Transformers
50 to 12.5 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***
Frequency
Unbalanced
Port
Impedance
Balanced
Port
Impedance*
Return
Loss
Insertion
Loss
MHz Ohms Ohms dB min dB max
800-1000 50 12.5+j 15 0.48
869-894 50 12.5+j 15 0.35
925-960 50 12.5+j 15 0.40
Amplitude
Balance
Phase
Balance
Power
Handling
Θ
ΘΘ
ΘJC
Operating
Temp.
dB max Degrees max Watts ºC / Watt ºC
0.40 180± 5.0 250 3.8 -55 to +85
0.40 180± 5.0 250 3.8 -55 to +85
Features:
• 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
0.40 180± 5.0 250 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. * 12.5
Ω
reference to ground
Outline Drawing
3A412S Mechanical Outline
Dimensions are in Inches [Millimeters]
Top View (Near-side) Bottom View (Far-side)
.075
±.008
[1.91
±0.20
]
Side View
Pin 1 Denotes
Array Number
1.000
±.010
[25.40
±0.25
]
.750
±.010
[19.05
±0.25
]
Pin 2 Pin 3
GND
.115
±.004
[2.92
±0.10
]
Pin 1GND
.050
±.008
[1.27
±0.20
]
.030
±.004
TYP
[0.76
±0.10
]
.400
±.004
[10.16
±0.10
]
.070
±.008
[1.78
±0.20
]
.060
±.004
[1.52
±0.10
]
.050
±.008
[1.27
±0.20
]
.030
±.004
[0.76
±0.10
]
Pin 3 Pin 2
.358
±.008
[9.09
±0.20
]
USA/Canada:
Toll Free:
Europe:
(315) 432-8909
(800) 544-2414
+44 2392-232392
Available on Tape and
Reel For Pick and Place
Manufacturing.
Model 3A412S
Rev A
Typical Performance: 700 MHz. to 1100 MHz.
Pin Configuration Mounting Configuration
Dimensions are in Inches [Millimeters]
3A412S Mounting Footprint
.291 [7.40]
.030 TYP
[0.76]
.070
[1.78] .115 [2.92]
.650
[16.51]
.080 [2.03]
2 Places
12.5 Transmission Line
Referenced to GND
.410 [10.41] .050 [1.27]
To ensure proper electrical and thermal performance
there must be a ground plane with 100%
solder connection underneath the part
.034 [0.86]
.080 [2.03]
.030
[0.76]
50 Transmission Line
Multiple
plated thru holes
to ground
.075 [1.90]
Amplitude Balance 3A412S
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
700 800 900 1000 1100
Frequency [MHz]
Amplitude Balance [dB]
Phase Balance 3A412S
-190
-185
-180
-175
-170
700 800 900 1000 1100
Frequency [MHz]
Phase Balance [Degrees]
Insertion Loss 3A412S
-0.5
-0.4
-0.3
-0.2
-0.1
0
700 800 900 1000 1100
Frequency [MHz]
Insertion Loss [dB]
-40
-30
-20
-10
0
700 800 900 1000 1100
Frequency [MHz]
Return Loss [dB]