LL1545A

      Tibeliusgatan 7 S-761 50 NORRTÄLJE SWEDEN Phone Fax International +46 - 176 13930 +46 - 176 13935 Domestic 0176-13930 0176-13935 Audio Transformer LL1545A LL1545A is a general-purpose audio transformer with a variety of connection alternatives. The transformer is built up from two coils, each with a secondary winding surrounded by shields and two primary windings. This structure results in an excellent frequency response. The transformer can be used in many different applications such as a high impedance line input transformer (accepting signal levels of 22 dBU @ 40 Hz with primaries in series), for splitting or as a microphone input transformer. The LL1545A is made with a mu-metal core and is housed in a mu-metal can. Refer to page 2 of this sheet for termination alternatives. Turns ratio: 1+1+1+1:2+2 Dims: (Length x Width x Height above PCB (mm)) 37 x 22.5 x 14.5 Pin Layout (viewed from component side) and Windings Schematics: 8 7 6 5 4 3 2 1 16 15 14 13 11 10 9 1 2 3 4 8 7 6 5 9 10 11 14 16 15 Can + Core 13 LL1545A (top view) Spacing between pins: Spacing between rows of pins: Weight: Rec. PCB hole diameter: Static resistance of each primary (average): Static resistance of each secondary (average): Self resonance point: Recommended load for best square-wave response (Termination alternative A below): Frequency response (source 600Ω , load (6.7 kΩ + 470 pF) in parallel with 56 kΩ ): Loss across transformer (at midband with termination as above): Core: Isolation between windings / between windings and shields: 2.54 mm (0.1") 22.86 mm (0.9") 46 g 1.5 mm 147 Ω 295 Ω > 220 kHz 6.7 kΩ + 470 pF 10 Hz - 70 kHz +/- 0.5 dB @ 0 dBU 0.3 dB Mu-metal 3 kV / 1.5 kV Data at different termination alternatives, showed on page 2 of this data sheet. Termination Turns Copper Resistance Idle impedance Suggested Use THD < 0.2%@40 Hz Alternative ratio prim/sec @40 Hz, 0dBU primary level / real source impedance A 1:1 590 Ω / 590 Ω 80 kΩ / 80 kΩ 10 kΩ / 10 kΩ 22 dBU / 600 Ω B 1:1 147 Ω / 147 Ω 20 kΩ / 20 kΩ 600 Ω / 600 Ω 16 dBU / 150 Ω C 1:2 147 Ω / 590 Ω 20 kΩ / 80 kΩ 600 Ω / 2.5 kΩ 16 dbU / 150 Ω D 1:2 37 Ω / 147 Ω 5 kΩ / 20 kΩ 200 Ω / 1 kΩ 10 dBU / 37.5 Ω E 1:4 37 Ω / 590 Ω 5 kΩ / 80 kΩ 200 Ω / 3.2 kΩ 10 dBU / 37.5 Ω F (Split) 2:1+1 590 Ω / 295 Ω + 295 Ω G (Split) 1:1+1 147 Ω / 295 Ω + 295 Ω Left side can also be connected as BCenterTap (1:1+1) or D (1:2+2) R000113 LL1545A , page 1 LL1545A Connection alternatives (Left side is input if not stated otherwise) !!!! Pin side view !!!! 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 5 6 7 8 A CENTER TAP 9 10 11 13 14 15 16 A 13 14 15 16 CT 1 2 3 4 5 6 7 8 B 9 10 11 13 14 15 16 CT 1 2 3 4 5 6 7 8 B CENTER TAP 9 10 11 13 14 15 16 1 2 3 4 5 6 7 8 C 9 10 11 13 14 15 16 CT 1 2 3 4 5 CENTER TAP 6 7 8 C 9 10 11 13 14 15 16 1 2 3 4 5 6 7 8 9 10 11 D 13 14 15 16 1 2 3 4 5 6 7 8 9 10 11 E 13 14 15 16 OUT 1 OUT 2 1 2 3 4 5 6 7 8 F SPLIT 9 10 11 13 14 15 16 IN + IN - 1 2 3 4 5 6 7 8 G SPLIT 9 10 11 13 14 15 16 OUT 1 Out 1 GND In GND Out2 GND OUT 2 LL1545A , page 2