CPC9909EB: Off-Line 350mA LED Driver

Clare's CPC9909 Evaluation Board contains all the necessary circuitry to demonstrate all the features of CPC9909 High Brightness (HB), Off-Line LED driver. The CPC9909 IC architecture includes pulse frequency modulation (PFM) with a constant peak-current control scheme. This regulation scheme is inherently stable, allowing the driver to operate above 50% duty cycle without open-loop instability or sub-harmonic oscillations. This greatly increases the number of LEDs in series that can be driven by the CPC9909 and by this Evaluation Board.

Linear LED dimming can be achieved either by adjusting the on-board potentiometer, RA1, or by adjusting the voltage at the LD pin. In addition, PWM dimming can be achieved with a user-applied TTL-level, low frequency, pulse-width-modulated square wave signal between JP1-1 (GND) and JP1-2 (connected to the PWMD pin of the CPC9909).