
High Level General Purpose Transformer
LL1684
LL1684 is a high-level, general-purpose, amorphous core transformer which can be used for microphone or line input,
for line output and for galvanic isolation. The windings are arranged to give perfect symmetry if the transformer is
used in phase splitting input applications. The two coils structure also greatly improves immunity to external magnetic
fields from e.g. power supplies and motors. Primary and secondary windings are separated by electrostatic shields..
The transformer is housed in a mu-metal can.
Turns ratio: 1 + 1 : 1 + 1
Pin layout (viewed from component side) and winding schematics:
Dimensions (L x W x H above PCB, in mm)
42 x 28 x 22
Spacing between pins
5.08 mm (0.2")
Spacing between rows of pins
30.5 mm (1.2")
Rec. PCB hole diameter:
1.5 mm
Weight:
81 g
Static resistance of each primary:
41Ω
Static resistance of each secondary:
41Ω
Distortion (primaries connected in series,
source impedance 150Ω ):
+ 23 dBU 0.1% @ 50 Hz
+ 25 dBU < 1 % @ 50 Hz
Distortion (primaries connected in parallel,
source impedance 150Ω ):
+ 16 dBU 0.1% @ 50 Hz
+ 19 dBU < 1 % @ 50 Hz
Self resonance point:
> 250 kHz
Frequency response (source 150Ω, load 10 kΩ,
serial connection):
10 Hz -- 100 kHz +/- 1.0 dB
Phase response (deviation from linear phase)
20 Hz – 20kHz, +/- 0.5°
Suggested load for best square wave response
10k // 1k + 3nF
Isolation between windings/ between windings and shield: 3 kV / 1.5 kV
Connection alternatives and suggested applications:
R030624
Parallel-parallel connection (1 : 1)
for low loss isolation application
Serial-serial connection (1 : 1) for high level line
isolation
TRANSFORMERS
Tibeliusgatan 7 International Domestic
S-761 50 NORRTÄLJE Phone +46 - 176 13930 0176-13930
SWEDEN Fax +46 - 176 13935 0176-13935
LL1684
Top view
LL1684
Top view
Centertap
LL1684
Top view
Phase splitting
for 1 : 1+1 input
LL1684
Top view