Lundahl Isolation transformer, LL1527A

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

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?
Static resistance of each secondary: 45?
Distortion (primaries connected in series, source impedance 800? ): + 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?
Frequency response (source 800? , load 4 k? 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