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IV. Wave-Shape Selection
The D381A driver IC uses a patented wave-shaping technique for reducing audible noise from an EL lamp. The linear
discharge of the output waveform may be adjusted by selecting a proper value for the wave-shaping resistor (Rena) to
the E pin. The optimal discharge level for an application depends on the lamp size, lamp brightness, and application
conditions. To ensure that the D381A is configured optimally, various discharge levels should be evaluated. In many
cases, the lower discharge levels result in lower audible noise from the EL lamp.
9
Typical waveshapes corresponding to the various discharge levels for a 4in2 lamp are shown below. The waveshape
with the smoothest transition slope in the discharge portion of the waveform yields the lowest audible noise.
R
ena=0Ω
R
ena=82kΩ
Figure 6: Rena selection for discharge control (CLOAD=15nF), (E= 3V)
D381 Discharge Control
0.00
2.00
4.00
6.00
8.00
10.00
12.00
0.0
20.0
40.0
60.0
80.0
100.0
Rena (KOhm)
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