AIC3643的特性及應用

Built-in OVP White LED Step-Up Converter Download Complete Datasheet PDF

FEATURES
Built-In Open Circuit Protection
Over Voltage Protection
Efficiency Up to 83% at VIN=4.2V, 3LEDs, ILED=20mA
1.2MHz Fixed Switching Frequency
Drives Up to 5LEDs in series
2.5V to 5.5V Input Voltage
Low Supply Current: 150冚A
Matches LED Current
Requires Tiny Inductor and Capacitors
TSOT-23-6, and SOT-23-6 Packages

APPLICATIONS
Cellular Phones
PDAs
DSCs
Handheld Devices
White LED Display Backlighting
DESCRIPTION
AIC3643 is a current-mode pulse-width-modulation (PWM), step-up DC/DC converter designed to drive white LEDs with a constant current to provide backlight in hand-held devices. Series connection of LEDs provides identical LED currents resulting in uniform brightness. This configuration eliminates the need of ballast resistors. The built-in open load protection prevents the damage resulting from an open circuit condition. Also low 100mV feedback voltage minimizes power loss in the current setting resistor for better efficiency.

AIC3643 is a step-up PWM converter, which includes an internal N-channel MOSFET switch for high efficiency. The high switching frequency, 1.2MHz, allows the use of tiny external components.

AIC3643 is available in a space-saving TSOT-23-6, and SOT-23-6 packages.

?AIC3643 datasheet,pdf