SP4423 Datasheet, PDF (5/13 Pages) Sipex Corporation – Electroluminescent Lamp Driver Low Power Applications

Electroluminescent backlighting is ideal when
used with LCD displays, keypads, or other backlit
readouts. Its main use is to illuminate displays in
dim to dark conditions for momentary periods
of time. EL lamps typically consume less than
LEDs or incandescent bulbs making them ideal
for battery powered products. Also, EL lamps
are able to evenly light an area without creating
"hot spots" in the display.
The amount of light emitted is a function of the
voltage applied to the lamp, the frequency at
which it is applied, the lamp material used and
its size. There are many variables which can be
optimized for specific applications. Sipex
supplies characterization charts to aid the
designer in selecting the optimum circuit
configuration (see page 6).
HON=V_DD=ON
HON=0V=OFF
V_IN=3V ₊
–
NOTE:
Keep coil as close to the
SP4423 as possible
Typical SP4423 Application Circuit
HON
V_SS
Coil
C_OSC=100pF
Cap2
Cap1
V_DD
0.1µF Low ESR
Decoupling
Capacitor
EL2
EL1
SP4423
EL Lamp
NOTE:
Keep high voltage traces
short and away from V_DD
and clock lines
HON=V_DD=ON
HON=0V=OFF
V_IN=3V ₊
–
NOTE:
Keep coil as close to the
SP4422A as possible
HON
V_SS
Coil
C_OSC=150pF
Cap2
Cap1
V_DD
0.1µF Low ESR
Decoupling
Capacitor
EL2
EL1
100Ω
SP4423
6nF
NOTE:
Keep high voltage traces
short and away from V_DD
and clock lines
Typical SP4423 Test Circuit
SP4423DS/14
SP4423Electroluminescent Lamp Driver
5
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