Current range control circuit, data driver, and organic light emitting display

An organic light emitting display comprising:

• a scan driver configured to sequentially supply a scan signal to a plurality of scan lines;
• a data driver configured to supply a data current to a plurality of data lines, wherein the data driver comprises
• a shift register configured to output a latch control signal according to a clock signal and a synchronous signal,
• a data latch configured to sequentially receive video data according to the latch control signal, and to output the video data in parallel,
• a multiplexer configured to multiplex the parallel video data,
• a digital-to-analog (D/A) converter configured to convert the multiplexed video data to multiplexed analog current, and to output multiplexed data current, and
• a current range control circuit configured to receive the multiplexed data current from the D/A converter and to output demultiplexed data current, wherein the current range control circuit is further configured to adjust a range of the data current according to a current range control signal;
• and
• a pixel portion configured to display an image according to the data current supplied to the plurality of data lines and the scan signal supplied to the plurality of scan lines.

A current range control circuit comprising:

• an input mirror circuit comprising a first transistor, wherein a drain and a gate of the first transistor are commonly connected, and wherein an input current is drawn from a drain of the first transistor;
• a master circuit configured to store a voltage corresponding to a voltage supplied to the gate of the first transistor, and to output a master current corresponding to the stored voltage according to a master sample and hold control signal, wherein a range of the master current value is controlled by the current range control signal;
• a slave circuit configured to store a voltage corresponding to the voltage supplied to the gate of the first transistor, and to output a slave current corresponding to the stored voltage according to a slave sample and hold control signal, wherein a range of the slave current is controlled by the current range control signal;
• and
• a master/slave selection circuit configured to output one of the master current and the slave current as a data current according to a master/slave selection circuit.

A current range control circuit comprising:

• an input mirror circuit comprising a first transistor and an operational amplifier, wherein a drain and a gate of the first transistor are commonly connected and an input current is drawn from a drain of the first transistor, wherein the operational amplifier forms a negative feedback loop comprising a positive input terminal of the operational amplifier connected to the drain of the first transistor;
• a master circuit configured to store a voltage supplied to the gate of the first transistor, and to output a master current corresponding to the stored voltage according to a master sample and hold control signal, wherein a range of the master current is controlled by a current range control signal;
• a slave circuit configured to store a voltage supplied to the gate of the first transistor, and to output a slave current corresponding to the stored voltage according to a slave sample and hold control signal, wherein a range of the slave current is controlled by the current range control signal;
• and
• a master/slave selection circuit configured to output one of the master current and the slave current as a data current according to a master/slave selection signal.

A method of generating video data current having different ranges for use in different types of display devices, the method comprising:

• multiplexing parallel video data;
• converting the multiplexed video data to multiplexed analog data current;
• demultiplexing the analog data current;
• and
• adjusting a range of the data current according to a current range control signal.

A circuit for generating video data current having different ranges for use in different types of display devices, the circuit comprising:

• means for multiplexing parallel video data;
• means for converting the multiplexed video data to multiplexed analog data current;
• means for demultiplexing the analog data current;
• and
• means for adjusting a range of the data current according to a current range control signal.