The KF9909A is a step-up DC/DC converter specifically designed for driving white LEDs with a constant curent. The intermal MOSFET can support up to 10 White LEDs for backlighting and OLED power application, and the intemal soft start function can reduce the inrush current. The KF9909A uses current mode, fixed frequency of approximately 1.0MHz architecture to regulate the LED current through an extermal current sense resistor. The low feedback voltage of 300mV can minimize power dissipation.
Other features include current limit protection, thermal shutdown protection, under-voltage lockout (UVLO), and over-voltage function.
The KF9909A is available in space saving SOT-23-6L and DFN-8L (2mm x 2mm) packages.
Features
VIN Operating Range: 2.5V to 5.5V
Intermal Power N-MOSFET Switch
Wide Range for PWM Dimming (100Hz to200kHz)
1.0MHz Switch Frequency
300mV Feedback Voltage
1.2A SW Current Limit
Minimize the External Component Counts
Internal Compensation
Over Voltage Protection
Application
Cellular Phones and Digital Cameras
PDAs and Smart Phones and MP3 and OLED
Portable Instruments
High-light LED Flash