| 摘要 |
PURPOSE:To save the power of the LED driving IC of a light transmitter. CONSTITUTION:N pieces of LED driving circuits and one piece of reference voltage supply circuit are made to one set, and m sets of parallel LED driving circuits 41-4m are accommodated in one LED driving IC. Power terminals VH2 and VL3 for supplying the clamp potential of an IC1 and the substrate potential and power terminals VA and VB for operating circuits are provided separately, and power terminals VH2 and VL3 for supplying the clamp potential of an IC1 and the substrate potential are made common for all circuits, and power terminals VA71-VA7m and VB81-VB8m for operating circuits are provided independently for each set. Hereby, for the power terminal of an unused circuit, the consumption of the current through its circuit can be suppressed and the power saved by giving, for example, substrate potential. |
