Operational amplifier, load driving apparatus and grayscale voltage generating circuit

An operational amplifier applicable to a grayscale voltage generating circuit in a display device, the operational amplifier having multiple output stages, the operational amplifier comprising:

• an input stage;
• an output stage selection module, comprising a plurality of signal transmitting paths;
• and
• a first output stage and a second output stage, wherein the first output stage is configured to be coupled to drive a first load, and the second output stage is configured to be coupled to drive a second load,
• wherein each of the signal transmitting paths is coupled between the input stage and a corresponding one of the output stages,
• wherein one of the signal transmitting paths is conducted to couple one of the output stages to the input stage, and the rest of the signal transmitting paths are disconducted to decouple the rest of the output stages with the input stage, such that the same input stage is configured to be coupled to a different one of the output stages and only one of the loads is driven,
• wherein the first load is a first gamma resistor string and the second load is a second gamma resistor string, each of the plurality of gamma resistor strings is configured to be driven by the respective output stage so as to generate a respective grayscale voltage.

A load driving apparatus applicable to a grayscale voltage generating circuit in a display device, the load driving apparatus having multiple output stages, the load driving apparatus comprising:

• a load driving module, comprising an input stage and a gain stage, configured to provide a driving signal at least one node;
• an output stage selection module, coupled to the load driving module to receive the driving signal;
• and
• a first output stage a second output stage, wherein the first output stage is coupled to the output stage selection module and is configured to be coupled to drive a first load, and the second output stage is coupled to the output stage selection module and is configured to be coupled to drive a second load,
• wherein the output stage selection module is configured to couple one of the output stages to the at least one node of the load driving module and decouple the rest of the output stages to the at least one node of the load driving module according to a plurality of selection signals, such that the at least one node is configured to be coupled to a different one of the output stages and only one of the loads is driven,
• wherein the first load is a first gamma resistor string and the second load is a second gamma resistor string, each of the plurality of gamma resistor strings is configured to be driven by the output stage so as to generate a respective grayscale voltage.

A load driving apparatus applicable to a grayscale voltage generating circuit in a display device, the load driving apparatus having multiple output stages, the load driving apparatus comprising:

• a load driving module, comprising an input stage and a gain stage, configured to provide a driving signal at least one node;
• an output stage selection module, comprising a plurality of signal transmitting paths;
• and a first output stage and a second output stage, wherein the first output stage is configured to be coupled to drive a first load, and the second output stage is configured to be coupled to drive a second load,
• wherein each of the signal transmitting paths is coupled between the at least one node of the load driving module and a corresponding one of the output stages,
• wherein one of the signal transmitting paths is conducted to couple one of the output stages to the at least one node of the load driving module, and the rest of the signal transmitting paths are disconducted to decouple the rest of the output stages with the at least one node of the load driving module, such that the at least one node is configured to be coupled to a different one of the output stages and only one of the loads is driven,
• wherein the first load is a first gamma resistor string and the second load is a second gamma resistor string, each of the plurality of gamma resistor strings is configured to be driven by the output stage so as to generate a respective grayscale voltage.

A grayscale voltage generating circuit, comprising:

• a first gamma resistor string and a second gamma resistor string, each for generating a plurality of grayscale voltages according to a plurality of driving signals;
• and
• a plurality of load driving apparatuses, each coupled to the first gamma resistor string and the second gamma resistor string, wherein each of the load driving apparatuses comprises:
• a load driving module, comprising an input stage and a gain stage, configured to provide a driving signal at least one node according to a gamma voltage;
• an output stage selection module, coupled to the load driving module to receive the driving signal;
• and
• a first output stage and a second output stage, wherein each of the output stages is coupled to the output stage selection module, the first output stage is coupled to drive the first gamma resistor string, and the second output stage is coupled to drive the second gamma resistor string,
• wherein the output stage selection module is configured to couple one of the output stages to the at least one node of the load driving module and decouple the rest of the output stages to the at least one node of the load driving module according to a plurality of selection signals, such that the at least one node is configured to be coupled to a different one of the output stage and only one of the gamma resistor strings is driven.

A grayscale voltage generating circuit, comprising:

• a first gamma resistor string and a second gamma resistor string, each for generating a plurality of grayscale voltages according to a plurality of driving signals;
• and
• a plurality of load driving apparatuses, each coupled to the first gamma resistor string and the second gamma resistor string, wherein each of the load driving apparatuses comprises:
• a load driving module, comprising an input stage and a gain stage, configured to provide a driving signal at least one node according to a gamma voltage;
• an output stage selection module, comprising a plurality of signal transmitting paths;
• and
• a first output stage and a second output stage, wherein the first output stage is coupled to drive the first gamma resistor, and the second output stage is coupled to drive the second gamma resistor,
• wherein each of the signal transmitting paths is coupled between the at least one node of the load driving module and a corresponding one of the output stages,
• wherein one of the signal transmitting paths is conducted to couple one of the output stages to the at least one node of the load driving module, and the rest of the signal transmitting paths are disconducted to decouple the rest of the output stages with the at least one node of the load driving module, such that the at least one node is configured to be coupled to a different one of the output stages and only one of the gamma resistor strings is driven.