D356A Datasheet, PDF (10/12 Pages) List of Unclassifed Manufacturers – Electroluminescent Lamp Driver IC

V. High EL Brightness Through Supply Voltage Doubling (Option 1)
Maximum brightness from a D356A is achieved at relatively high supply voltages (>3.0V). An external voltage boost
circuit may be used to increase the voltage supplied to the D356A. In the following circuit, the National
Semiconductor LM2665 is used to double the voltage supplied to the D356A. This can produce about twice the
brightness of the D356A alone.
3.3uF
Vbat
1 V _BAT CAP+ 6
1N914
2 GND OUT 5
OFF
Vbat
3 CAP- SD 4
LM2665
ON
ON
1 GND
E8
OFF
2 L-
CLF2 7
CLF
L
3 VOUT
CLF1 6
4 L+
D356
V+ 5
EL Lamp
3.3uF
VI. High EL Brightness Through Supply Voltage Doubling (Option 2)
In many cases, a resistor may replace the diode in the previous circuit. The diode is used by the LM2665 during
startup (see LM2665 datasheet). The circuit below ensures that the LM2665 starts properly before the D356A is
turned on.
3.3uF
Vbat
V bat
L
1 V _BAT CAP+ 6
2 GND OUT 5
3 CAP- SD 4
LM2665
1 GND
E8
270KΩ
OFF
ON
Vbat
2 L-
CLF2 7
CLF
3 VOUT
CLF1 6
4 L+
D356
V+ 5
EL Lamp
3.3uF
10