Patent ID: 6967604
Filing Date: 2005-11-22
Classification: G09G,H03M

Abstract:
1. A D/A converter circuit for driving directly or indirectly an organic EL display panel, including a current mirror circuit constructed with an input side transistor circuit and an output side transistor circuit, said organic EL display panel being a self-emissive type display panel that uses organic materials formed into thin films and that is driven by electric current to generate light, said input side transistor circuit comprising: a series circuit of a first MOS transistor and a second MOS transistor; and a first switch circuit connected in parallel to said fist MOS transistor, gates of said first and second MOS transistors being connected commonly, a source of either one of said first and second MOS transistors being connected to a drain of the other of said first and second MOS transistors and said second MOS transistor having a gate length shorter than a gate length of said first MOS transistor, either one of a non-connected source and a non-connected drain of said first and second MOS transistors being connected to a power source line of a predetermined voltage, directly or indirectly, said first switch circuit being turned ON to supply a current larger than a current determined by a source-gate voltage between said gate and said non-connected source of one of said first and second MOS transistors, the source-gate voltage being limited by said predetermined voltage, to said series circuit to thereby obtain a large analog current at said output side transistor circuit of said current mirror circuit.