
Microphone Input Transformer
LL1571
LL1571 is a microphone input transformer built up from two coils and a high permeability mu metal core.
Each coil is wound in three sections with electrostatic shields connected to separate pins. This result in a
transformer with a very broad band, also ideal for splitting purpose. The two-coil structure in combination with
the mu-metal can results in a high immunity to external magnetic fields.
Turns ratio: 1 + 1 : 1.75 + 1.75
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 rows from adjacent rows: 2.54 mm (0.1")
Weight: 48 g
Rec. PCB hole diameter: 1.5 mm
Static resistance of each primary: 50
Ω
Static resistance of each secondary: 175
Ω
Distortion (primaries 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
(Source imp. 800
Ω,
primaries and secondaries in series): 4 k
Ω
in series with 0.3 nF
Frequency response (source and load as above ): 10 Hz -- 100 kHz +/- 0.5 dB
Isolation between windings/ between windings and shield: 4 kV / 2 kV
Connections:
1 : 1.75
Serial - serial connection
1:3.5
Parallel-serial connection
+
E1
EP
3
2
1
8
7
6
4
5
E2
E1
EP
3
2
1
8
7
6
4
5
E2
+
R980616
Can and core connected to EP
E 2
E 1
2
1
3
4
6
5
7
8
3
2
1
8
7
6
4
5
E1
E2
EP
Tibeliusgatan 7 International Domestic
S-761 50 NORRTÄLJE Phone +46 - 176 13930 0176-13930
SWEDEN Fax +46 - 176 13935 0176-13935
LL1571
(top view)