SEMICONDUCTOR
TECHNICAL DATA
White LED Step-Up Converter
The KAB3403T/DN is a monolithic step-up DC/DC converter specifically
designed to drive white LEDs with a constant current from Li-ion cell.
Relative large 320mV feedback voltage & it s high accuracy help you
setting LED current with a external resistor.
KAB3403T/DN is available in a extremely low profile & small TS-6
package.
A 10 H inductor is sufficient for most application.
FEATURES
Inherently Matched LED Current.
High Efficiency : 87% (max.)
C
KAB3403T/DN
BICD LINEAR INTEGRATED CIRCUIT
E
K
B
K
1
G
6
2
5
DIM
A
B
C
D
E
F
G
H
I
J
K
L
D
3
4
MILLIMETERS
_
2.9 + 0.2
1.6+0.2/-0.1
_
0.70 + 0.05
_
0.4 + 0.1
2.8+0.2/-0.3
_
1.9 + 0.2
0.95
_
0.16 + 0.05
0.00-0.10
0.25+0.25/-0.15
0.60
0.55
A
F
L
G
Built in a open circuits protection for the LEDs fail.
Drives Up to Five LEDs
Built in a N-channel MOSFET Switch.
Fast 1.1MHz(typ.) Switching Frequency.
Wide Dimming control range : 12%~100%.
Automatic Soft-Start
Bulit in OVD (Over voltage protection.)
Extremely low height & small Packaging.
J
APPLICATIONS
Celluar Phones
Smart Phones
PDAs
Digital Cameras
MP3 Players, Color Displays
C
D
A
A
E
Marking
6
Type Name
5
4
Lot No.
DIM
A
B
C
D
E
F
G
H
I
J
MILLIMETERS
_
2.00
+
0.10
_
1.60
+
0.10
_
0.30
+
0.05
0.65 Typ
_
1.00
+
0.10
_
0.10
0.25
+
Φ 0.25
_
0.75
+
0.05
0.0 + 0.05
0.20 Ref
J
403
Type Name
403
TDFN-6
1
2
3
Lot No.
KAB3403DN
KAB3403T
2007. 2. 26
Revision No : 0
I
H
F
I
J
H
TS6
B
G
1/7
KAB3403T/DN
TYPICAL APPLICATION
L1
4.7µH ~ 22µH
V
IN
D1
V
OUT
CONVERSION EFFICIENCY
90
LED1
OVD
LED2
LED3
LED4
C2
1µF
EFFICIENCY (%)
C1
1µF
V
CC
SW
85
80
75
70
65
60
0
5
10
15
20
25
30
35
KAB3403T/DN
ON
OFF
Shutdown and
Dimming control
CTL
GND
FB
VFB
R1
16Ω
3.0V
3.6V
4.3V
5.0V
LOAD CURRENT (mA)
BLOCK DIAGRAM
V
CC
SW
OVD
I sens
Comparator
R
S
Q
Driver
OVER
VOLTAGE
DETECTION
Ramp
Generator
1.1MHz
Oscillator
GND
Soft
Start
FB
Error
Amp
Reference
Generator
Vref (320mV)
Shutdown
CTL
Dimming
figure 2. KAB3403T/DN Block Diagram
PIN FUNCTIONS
NO.
SYMBOL
KAB3403T
6
5
4
3
2
KAB3403DN
1
2
3
4
5
V
CC
GND
FB
SW
OVD
Input supply pin. Must be locally bypassed.
Ground pin. Connect directly to local ground plane,
Feedback pin. Reference voltage is 320mV. Connect cathode of lowest LED and resistor here.
Switch pin. Connect inductor/diode here. Minimize trace area at this pin to reduce EMI.
Over output voltage detect pin. Connect cathode of schottky diode and anode of highest LED.
Control pin : Shutdown or dimming control. Connect external enable or dimming circuits.
1
6
CTL
Shutdown mode (IF = 0) : V
CTL
<1.0V
Dimming control mode : (IF = 12% ~ 100%, depend on V
CTL
)
FUNCTION AND CONNECTION.
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Revision No : 0
2/7
KAB3403T/DN
MAXIMUM RATINGS (Ta=25
)
SYMBOL
V
CC
V
SW
V
OVD
Topr
Tstg
Tj
RATING
-0.3 ~ 6.0
-0.3 ~ 22
-0.3 ~ 22
-40 ~ 85
-55 ~ 150
150
UNIT
V
V
V
CHARACTERISTICS
Input Voltage
Switching pin Voltage
OVD pin Voltage
Operating temperature range
Storage temperature range
Maximum Junction temperature
RECOMMENDED OPERATING CONDITIONS (T
opr
=-40~85
CHARACTERISTICS
Input Voltage
CTL pin voltage for full LED current
CTL pin voltage to shutdown chip
LED Current
CTL Response Delay
(When Power ON.)
SYMBOL
V
CC
V
CTL
H
V
CC
=3.0V
V
CTL
L
IF
T
pd
CTL
)
MIN.
2.7
2.7
-
TYP.
-
-
-
20
-
MAX.
5.5
-
0.5
-
-
UNIT
V
V
V
CONDITION
-
V
CC
=3.6V, R
SENSE
=16 ,
Topr =25 , Five LED
-
-
2
ELECTRICAL CHARACTERISTIC
(Topr=-40~85 , V
CC
=2.7~5.5V, R
SENSE
=16 , unless otherwise noted.)
CHARACTERISTICS
Input Voltage
Supply Current
Feedback Voltage
CTL Pin Bias Current
Switching Frequency
Switching Pin Current
Switch Leak Current
OVD Pin Voltage
OVD Pin Leak Current
Switching Pin OVP
CTL pin voltage for Full LED Current
CTL pin voltage to shutdown Chip
Feedback Bias Current
Maximum Duty Cycle
SYMBOL
V
CC
I
CC
V
FB
I
CTL
f
OSC
I
O(SW)
I
OZ(SW)
V
OVD
I
OZ(OVD)
V
O(SW)
V
CTL H
V
CTL L
I
FB
D
max
V
CC
= 3.0V
-
-
V
OVD
= 18V
-
-
-
CONDITION
-
V
CC
= 3.6V, V
CTL
=3.6V
V
CTL
= 0V
V
CC
=V
CTL
=3.0V, T
opr
= 25 , L =4.7 H
V
CC
= 3.0V, V
CTL
= 3.0V
V
CTL
= 3.0V
MIN.
2.7
-
-
304
-
0.77
-
-
19
-
25
2.7
-
-
85
TYP.
-
0.9
0.5
320
5
1.1
400
0.5
21
0.5
-
-
-
0.5
90
MAX.
5.5
1.5
1
336
10
1.43
-
1
23
1
-
-
0.5
1
-
%
V
V
V
V
UNIT
V
2007. 2. 26
Revision No : 0
3/7
KAB3403T/DN
Inductor Section
A 10uH inductor is sufficient for most application. The efficiency
comparision of different value inductors help you design your
application circuits.
90
88
V
IN
=3.6, 4LED Inductor=Murata
86
84
82
80
78
76
74
72
70
68
66
64
62
60
0
5
15
20
10
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]
L1
4.7µH ~ 22µH
V
IN
D1
EFFICIENCY (%)
10µH
4.7µH
LED1
V
CC
SW
OVD
LED2
LED3
LED4
CTL
C1
1µF
GND
R1
16Ω
FB
C2
1µF
25
30
35
LOAD CURRENT (mA)
Figure3. Efficiency Comparison of different value inductors
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.
Part No.
KDR730E
Reverse
Forward
Voltage (V) Current (mA)
30
200 mA
Voltage
Drop (V)
0.6V (max)
at 200 mA
0.5V(max)
at 200 mA
0.5V(max)
at 500 mA
Package
1.60
1.20
0.80
1
0.30
KAB3403T/DN
Figure4. 4LEDs driver with Open-circuit protection.
L1
4.7µH~22µH
V
IN
LED1
SW
OVD
DZ
V
CC
LED2
LED3
LED4
C2
1µF
D1
KAB3403T/DN
CTL
C1
1µF
GND
FB
LED5
LED6
2
1.60
1.20
0.80
1
2
0.30
R1
16Ω
KDR720E
30
200 mA
1.25
Table1. Recommended Schottky Diode
0.30
KDR412
20
500 mA
2.50
1.70
Figure5. 6LEDs driver with Open-circuit protection.
Dimming Control
There are 4 different type of dimming control circuits;
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.
1. Using a DC Voltage to CTL pin
Description
Rate Of the LED Current
Example : R
SENSE
= 16
V
CTL
0V~0.5V 1V~2.5V V
CTL
>2.5V
0
0
25 ~ 100
5 ~ 20
100
20
UNIT
%
mA
Table 2 CTL pin Voltage vs I
LED
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Revision No : 0
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KAB3403T/DN
L1
4.7µH ~ 22µH
V
IN
V
CC
C1
1µF
SW
OVD
LED1
LED2
LED3
LED4
CTL
GND
R1
16Ω
FB
C2
1µF
V
IN
LED1
V
CC
SW
OVD
LED2
LED3
LED4
CTL
C1
1µF
Rsence
FB
R1
KTK5132V
LOGIC
4. Using a Logic Signal to FB pin.
D1
For application that need to adjust the LED current in discrete
steps. A logic signal can be used as shown in Figure 9.
L1
4.7µH ~ 22µH
D1
KAB3403T/DN
DC
KAB3403T/DN
GND
C2
1µF
Figure6. Using a DC Signal to CTL pin.
2. Using a filtered PWM Signal to CTL pin.
The filtered PWM signal can be considered as an adjustable DC
voltage. It can be used to replace the variable DC Voltage source
in dimming control. The circuit is shown in Figure 7
L1
4.7µH ~ 22µH
V
IN
LED1
C1
1µF
V
CC
SW
OVD
LED2
LED3
R1
15kΩ
PWM
Signal
C2
1µF
D1
Figure9. Using a Logic Signal to FB pin.
KAB3403T/DN
LED4
CTL
FB
GND
Rsence
D1
LED1
V
CC
SW
OVD
LED2
LED3
LED4
GND
FB
R2
Rsence
R1
C3
1µF
Figure7. Using a filtered PWM Signal to CTL pin.
3. Using a DC Voltage to FB pin.
The dimming control using a DC control voltage to FB pin of the
KAB3403T/DN is shown in Figure. The LED current can be
varied applying a DC voltage to the FB pin. The voltage can come
from a filtered PWM signal. It can be used to replace the variable
DC voltage source in dimming control.
L1
4.7µH ~ 22µH
V
IN
KAB3403T/DN
CTL
C1
1µF
C2
1µF
2007. 2. 26
Revision No : 0
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