GENERAL DESCRIPTION
Because it directly regulates output current, the PT4102 is ideal for driving light emitting diodes (LEDs) whose light intensity is proportional to the current passing through them, not the voltage across their terminals. A single external resistor sets LED current between 5mA and 20mA, which can then be easily adjusted using either a DC voltage or a pulse width modulated (PWM) signal. The output capacitor can be as small as 0.22uF. Its low 88/104mV feedback voltage reduces power loss and improves efficiency. The PT4102 is available in SOT-23-5 and SC-70 packages. FEATURES
APPLICATIONS
Built-in 40V Power MOSFET Drives Up to 8 Series White LEDs from 3.6V Up to 87% Efficiency 1.2MHz Fixed Switching Frequency Low Feedback Voltage:104mV for E-suffix, 88mV for S-suffix. PWM or DC Dimming Current Limit 0.22uF Output Capacitor Package: SOT-23-6 and SC-70 Cell Phones Handheld Computers and PDAs Digital Cameras Small LCD Displays TYPICAL APPLICATIONS
Figure 1.
