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Kingbor Technology |
Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
KB4314
High Efficiency, Constant Current
1 Watt Boost White-LED Driver
FEATURES
•Operating Voltage:1.8V~6.5V
•High Operating Frequency: 1.2MHz
•High Efficiency: Up to 92%
•High Output Voltage: Up to 30V(max)
•High Output Power: 1W
•Shutdown Current <1PA
•30V Output Over-voltage protection (min)
•Digital Dimming Control.
•Built-in Cycle-by Cycle Current-limiting.
•Built-in Soft-Start Function.
•0.105V Low Reference Voltage(+/-6.6%)
•Tiny SOT23-6 Package
APPLICATIONS
• LED Module
• LED Backlight for LCD Display (3.5”~6.5” )
• Constant Current Source!
DESCRIPTION
The KB4314 step-up converter drives white LEDs
with a constant current to provide backlight in cell
phones, PDAs, and other hand-held devices. It
features allowing series connection of the white
LEDs so that the LED currents are identical for
uniform brightness. An enable input can be pulsed
repeatedly to adjust LED’s brightness. The fast 1.2
MHz current-mode PWM control allows for smaller
capacitor and inductor. Fault condition protection
uses cycle-by-cycle current limiting to sense
maximum inductor current, thermal protection and
over-voltage protection. Also included soft-start
eliminates inrush current during start-up. The 0.105V
low reference voltage minimized the power loss
across the current-setting resistor.
The KB4314 is available in SOT23-6 packages/
SIMPLIFIED BLOC DIAGRAM
VIN
EN
FB
OVP
ON/OFF
Control
Logic / PWM
Dimming
Control
CTL
VREF(105mV)
+
-
VREF
0.105V
VBG
1.23V
Soft-Start
Control Logic
30V
VBG
+
Overvoltage
Protection
-
Current Limit
0.45A
+
-
N
CTL
GND
LX
REV: 1.0
1
Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
PIN CONFIGURATION
SOT23-6
KB4314
High Efficiency, Constant Current
1 Watt Boost White-LED Driver
Marking
ORDER INFORMATION
Part number
KB4314 GRE
Package
SOT23-6, Green
Marking
101, 1H 86 Date Code with one bottom line
PIN DESCRIPTION
Pin N0. Symbol
1 LX
2 GND
3 FB
4 EN
5 OVP
6 VIN
I / O Description
I Step-up Regulator N-MOS Drain. Place output diode and inductor.
P Ground
I
Step-Up Regulator Feedback Input. Connect a sense resistor from FB to
ground.
Enable and Dimming Control Input. LED brightness and IC shutdown are
I controlled by the voltage on EN. Driving low for longer than 4ms to
shutdown the IC.
I Over-voltage protection input. Connect to the output.
P Power supply.
REV: 1.0
ABSOLUTE MAXIMUM RATINGS (Note 1)
Parameter
VIN voltage
LX , OVP voltage
EN , FB to GND
Switch Current (ILX)
Continuous power dissipation (SOT23-6 Ta=+25 OC)
Operating Junction Temperature Range
Lead Temperature (Soldering 5 sec)
Storage Temperature
Package Thermal Resistance (ӘJA)
ESD Susceptibility (HBM)
ESD Susceptibility (MM)
Rated Value
-0.3 to +6.5
-0.3 to +30
-0.3 to +6.5
0.45
0.35
-35 to 85
260
-65 to 125
250
2
200
Unit
V
V
V
A
W
к
к
к
к/W
KV
V
Note1:Permanent device damage may occur if Absolute Maximum Ratings are exceeded. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability
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