D372A Datasheet, PDF (7/12 Pages) List of Unclassifed Manufacturers – Electroluminescent Lamp Driver IC

IV. Wave-Shape (Rd) Selection
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and discharge portions of the output waveform. The optimal value
conditions. Typical values range from 0Ω - 2.0kΩ. Recommended
starting values for various lamp sizes are shown in the table below. The optimal waveform is trapezoidal which will
result in the best combination of high brightness and low audible noise performance. Using a larger value of Rd than
recommended will result in a triangular waveform and correspond to reducing the audible noise of the EL lamp and
increase lamp life. However, the luminance of the EL lamp will decrease. Using a smaller value of Rd than recom-
mended will result in a square waveform and correspond to higher initial luminance from the EL lamp, but will not take
advantage of the noise reduction capability of the D372.
Rd
Lamp Size
1.2kΩ
820Ω
470Ω
220Ω
<1.0 in²
1.0-2.0 in²
2.0-4.0 in²
>4.0 in²
Typical waveforms corresponding to the selected R_d values for a 2in² lamp and a 4in² lamp are shown below.
Lamp Size 2 in²
Rd = 820 Ω
Optimal waveform for 2 in ²
Rd = 1.2k Ω
Reduced noise with lower luminance
Lamp Size 4 in²
Rd = 470 Ω
Optimal waveform for 4 in²
Rd = 0 Ω
Higher luminance with more noise
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