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參數(shù)資料
| 型號： | KDR720E |
| 廠商： | KEC Holdings |
| 英文描述： | White LED Step-Up Converter |
| 中文描述： | 白光LED升壓轉換器 |
| 文件頁數(shù)： | 4/7頁 |
| 文件大?。?/td> | 421K |
| 代理商： | KDR720E |
2007. 2. 26
4/7
KAB3403T/DN
Revision No : 0
Inductor Section
A 10uH inductor is sufficient for most application. The efficiency
comparision of different value inductors help you design your
application circuits.
Inductor Section
A 1uF input capacitor and output capacitor above 1uF are
sufficient for most KAB3403T/DN application.
Diode Selection
For Diode Selection, both forward voltage drop and diode
capacitance need to be considered. Schottky diodes with higher
current ratings usually have lower forward voltage and larger diode
capacitance, which can cause significant switching losses. A
schottky diode rated at 100mA to 200mA is sufficient for most
KAB3403T/DN applications.
LED Current Control
The LED current is controlled by the feedback resistor (RSENSE
in Figure 1). The feedback reference is 320mV. The LED current
is 320mV/RSENSE . The tolerance of LED Current is depends on
tolerance of RSENSE and feedback reference.
Open-Circuits Protection
In the case of output open circuit, when LEDs are disconnected
from the circuit or the LEDs fail, the feedback voltage will be zero.
The KAB3403T/DN will then switch at a high duty cycle resulting
in a high output voltage. But Internal Over Voltage Protection
Circuits prevent output voltage ascending over OVD pin
voltage(19V ~ 23V see Fig 4). This circuits is valid when driving
up to 4 LEDs in series. But, when driving more than 4 LEDs in
series, Normal output voltage could be over OVD pin voltage. In
this case, zener diode can be used to check connect of OVD pin to
LED anode.(see Fig 5) [Recommended Zener diode : KDZ3.0V]
Dimming Control
There are 4 different type of dimming control circuits;
1. Using a DC Voltage to CTL pin
Table 2 CTL pin Voltage vs I
LED
Part No.
Reverse
Voltage (V)
Forward
Current (mA)
Voltage
Drop (V)
Package
KDR730E
30
200 mA
0.6V (max)
at 200 mA
1.60
0
0
1
2
KDR720E
30
200 mA
0.5V(max)
at 200 mA
1.60
0
0
1
2
KDR412
20
500 mA
0.5V(max)
at 500 mA
0
1
1.70
2.50
LOAD CURRENT (mA)
10
E
74
72
70
68
66
64
62
60
82
80
86
84
90
88
78
76
0
5
30
15
35
20
25
4.7
μ
H
10
μ
H
V
IN
=3.6, 4LED Inductor=Murata
L1
4.7
μ
H ~ 22
μ
H
SW
C1
1
μ
F
C2
1
μ
F
D1
CTL
FB
OVD
LED1
LED2
LED3
LED4
GND
V
CC
V
IN
R1
16
V
CC
V
IN
GND
SW
C1
1
μ
F
C2
1
μ
F
R1
16
D1
D
CTL
FB
OVD
L1
4.7
μ
H~22
μ
H
LED1
LED2
LED3
LED4
LED5
LED6
KAB3403T/DN
KAB3403T/DN
Figure4. 4LEDs driver with Open-circuit protection.
Figure5. 6LEDs driver with Open-circuit protection.
Figure3. Efficiency Comparison of different value inductors
Table1. Recommended Schottky Diode
Description
V
CTL
UNIT
0V~0.5V 1V~2.5V V
CTL
>2.5V
0
25 ~ 100
Rate Of the LED Current
100
%
Example : R
SENSE
= 16
0
5 ~ 20
20
mA
相關PDF資料 |
PDF描述 |
|---|---|
| KDR730E | White LED Step-Up Converter |
| KDR720S | SCHOTTKY BARRIER TYPE DIODE(FOR HIGH SPEED SWITCHING CIRCUIT, FOR SMALL CURRENT RECTIFICATION) |
| KDR721S | SCHOTTKY BARRIER TYPE DIODE(CATHODE COMMAND) |
| KDR728E | SCHOTTKY BARRIER TYPE DIODE(LOW VOLTAGE HIGH SPEED SWITCHING) |
| KDR728 | SCHOTTKY BARRIER TYPE DIODE(LOW VOLTAGE HIGH SPEED SWITCHING) |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| KDR720F | 制造商:KEC 制造商全稱:KEC(Korea Electronics) 功能描述:SCHOTTKY BARRIER TYPE DIODE |
| KDR720S | 制造商:KEC 制造商全稱:KEC(Korea Electronics) 功能描述:SCHOTTKY BARRIER TYPE DIODE(FOR HIGH SPEED SWITCHING CIRCUIT, FOR SMALL CURRENT RECTIFICATION) |
| KDR720UL | 制造商:KEC 制造商全稱:KEC(Korea Electronics) 功能描述:SCHOTTKY BARRIER TYPE DIODE |
| KDR720V | 制造商:KEC 制造商全稱:KEC(Korea Electronics) 功能描述:LOW CURRENT RECTIFICATION AND HIGH SPEED SWITCHING |
| KDR721S | 制造商:KEC 制造商全稱:KEC(Korea Electronics) 功能描述:SOT-23 PACKAGE |
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