
Microphone Split Transformer / Line Bridging Transformer
LL1527A
LL1527A is a special split version of our classical microphone transformer LL1527, where the shields of the
two coils are available on separate pins. This facilitates building of e.g. split boxes with galvanically isolated
shields.
The LL1527 is built-up from two coils, each with one primary and one secondary winding separated by an
electrostatic shield. Each shield is connected to a separate pin. The core is a high permeability mu-metal core and
the transformer is housed in a mu-metal can.
Turns ratio: 1 + 1 : 1 + 1
Dims (Length x Width x Height above PCB (mm)): 38 x 24 x 17
Pin layout (viewed from component side) and winding schematics:
Spacing between pins: 5.08 mm (0.2")
Spacing between rows of pins: 27.94 mm (1.1")
Offset of earth pin row from adjacent row: 2.54 mm (0.1")
Weight: 48 g
Rec. PCB hole diameter: 1.5 mm
Static resistance of each primary: 42
Ω
Static resistance of each secondary: 45
Ω
Distortion (primaries connected in series, source impedance 800
Ω
): + 6 dBU 0.1% @ 50 Hz
+16 dBU < 1 % @ 50 Hz
Self resonance point : > 200 kHz
Optimum load for best square-wave response (sec. in series): 3 - 4 k
Ω
Frequency response (source 800
Ω
, load 4 k
Ω
serial connection): 10 Hz -- 150 kHz +/- 0.2 dB
Loss across transformer (at midband, with above termination): 0.6 dB
Isolation between windings/ between windings and shield: 4 kV / 2 kV
Termination alternatives and suggested applications:
R980616
+
3
2
1
8
7
6
4
5
E1
+
3
2
1
8
7
6
4
5
E1
+
+
Parallel-parallel connection (1 : 1)
for e.g. mic input
Serial-serial connection (1 : 1) for
line bridging
Parallel-split connection (1 : 1 + 1)
Parallel-serial connection (1 : 2) for
e.g. mic. input
Can and core connected to E1
3
4
2
1
E1
7
8
6
5
E2
E1
E2
+
3
2
1
8
7
6
4
5
+
E2
E2
E2
E1
E2
84
3
2
1
7
6
5
Tibeliusgatan 7 International Domestic
S-761 50 NORRTÄLJE Phone +46 - 176 13930 0176-13930
SWEDEN Fax +46 - 176 13935 0176-13935
LL1527A
(top view)