A LED driver based on pulse current modulator

This paper presents a LED driver based on pulse current modulator. The proposed pulse current modulator consists of a voltage-controlled oscillator (VCO), a pulse generator, a series buffer, a single stage amplifier, a power transistor, and a sense resistance. A complete analysis and introduction of the proposed pulse current driving technique and the conventional driving technique will be presented in this paper. The LED driver used in the pulse current modulator driving technique supplies pulse driving current between 0 mA~250 mA and operates between 500 kHz~1 MHz. The LED driver is fabricated with CMOS 0.35-μm 2P4M technology. The chip area with pads is 935μm × 956μm.