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參數(shù)資料
| 型號： | SP4480EN |
| 英文描述： | Dual Electroluminscent Lamp Driver |
| 中文描述： | 雙Electroluminscent燈驅動器 |
| 文件頁數(shù)： | 5/13頁 |
| 文件大小： | 128K |
| 代理商： | SP4480EN |
SP4480DS/06
SP4480 Dual Electroluminescent Lamp Driver
5
Copyright 2000 Sipex Corporation
lighting situations. These features make EL
ideal for attractive, battery powered products.
THEORY OF OPERATION
Coil Switch
The SP4480 has an inductor-based boost con-
verter to generate the high voltage used to drive
the EL lamp. Energy is stored in the inductor
according to the equation E
= 1/2 (LI
I
= (t
) (V
- V
) /L. An internal oscil-
lator controls the coil switch. During the time
the coil switch is on, the coil is connected
between V
and the saturation voltage of the
coil switch and a magnetic field develops in the
coil. When the coil switch turns off, the switch
opens, the magnetic field collapses and the volt-
age across the coil rises. The internal diode
forward biases when the coil voltage rises above
the H-Bridge voltage and the energy enters the
EL lamp. Each pulse increases the voltage
across the lamp in discrete steps.
2
) where
As the voltage approaches its maximum, the
steps become smaller. (see figure 4).
The brightness of the EL lamp output is directly
related to energy recovery in the boost con-
verter. There are many variations among coils
such as magnetic core differences, winding dif-
ferences and parasitic capacitances. For sug-
gested coil suppliers refer to page 10.
Oscillator
The internal oscillator generates a high fre-
quency clock used by the boost converter and H-
Bridge. An external resistor from VDD to
ROSC sets the oscillator frequency. Typically
a 402k
resistor sets the frequency to 57kHz.
The high frequency clock directly controls the
coil switch. This high frequency clock is di-
vided by 128 to generate a low frequency clock
which controls the EL H-Bridge and sets the EL
lamp frequency. The oscillator has low sensi-
tivity to temperature and supply voltage varia-
tions, increasing the performance of the EL
Figure 2: Typical Application Circuit of the SP4480
R
OSC
V
SS
COIL
CAP
SP4480
V
BATT
C1
0.1
μ
F
R
402k
L1
470
μ
H
8
14
3
1
9
7
ELEN1
D1
1N4148
C
1800pF
V
DD
EL2
EL1
EL Lamp
10
12
1nF
2
ELEN2
* optional device
EL4
EL3
13
11
EL Lamp
相關PDF資料 |
PDF描述 |
|---|---|
| SP4480EY | Dual Electroluminscent Lamp Driver |
| SP4480NEB | Dual Electroluminscent Lamp Driver |
| SP4490UEB | 320 x 240 pixel format, 5.7in. Display |
| SP4490 | Two Panel Electroluminscent Lamp Driver |
| SP4490EU | Two Panel Electroluminscent Lamp Driver |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| SP4480EY | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Dual Electroluminscent Lamp Driver |
| SP4480NEB | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Dual Electroluminscent Lamp Driver |
| SP448J | 制造商:Panasonic Electric Works 功能描述: |
| SP4490 | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Two Panel Electroluminscent Lamp Driver |
| SP4490EU | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Two Panel Electroluminscent Lamp Driver |
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