KB4314 Datasheet, PDF (1/9 Pages) Kingbor Technology Co – High Efficiency, Constant Current 1 Watt Boost White-LED Driver

Kingbor Technology Co.,Ltd
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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
LX
VREF
ON/OFF
0.105V
EN
Control
Logic / PWM
VBG
Soft-Start
Dimming
1.23V
Control
CTL
VREF(105mV)
+
FB
-
N
Control Logic
OVP
30V
VBG
+
Overvoltage
Protection
-
Current Limit
0.45A
+
-
CTL
GND
REV: 1.0
1