The KF9917 is a high efficiency step-up converter with an internally integrated 40V power MOSEFT. It runs with an optimal 0.8MHz frequency that enables use of small extemal components while still providing best efficiencies. It has an internal current limit as high as 1A, and it can drive up to 10 LEDs at 50mA output current. The incorporated 18-100KHz true PWM-Dimming feature by EN pin can be used to digitally program the LED current. For maximum protection，the KF9917 has an internal OVP protection at 38V to prevent the chip from damages when the LED string is not connected to the output.
KF9917 is available in a space saving SOT- 23-6 package.
Features
Up to 91% Efficiency (6 LEDs)
Drive up to 10 LEDs with 50mA
Drive up to 40 LEDs in total
38V OVP protection
True PWM Brightness Control
200mV Feedback Voltage
1A current limit
SOT-23-6 Package
Application
Cellphone and Smartphone
MID or Tablet PC
TFT-bias for L .CD screen
Power for OL .ED
LED torch
Satellite Set Top Box