Integratable, low loss multiple LED driver - uses microprocessor controlling LEDs arranged in groups of serial circuits, each contg. antiparallel pairs of LEDs

摘要

Each pair of LEDs (D1/D5) forms an antiparallel circuit, each of which forms a serial circuit with another antiparallel circuit. The serial circuits are divided into two groups (GR1, GR2) of equal size. The supply lines (C1-C4) of the serial circuits are multiplexed to a supply voltage, earth or a high impedance as required. The centre points of the circuits from the two groups are connected via a constant current source or to the supply voltage or to earth. ADVANTAGE - Enables large number of LEDs to be driven with low supply voltage of 5 volts and few external control lines.