Gamma adjustment circuit and display driver circuit using the same

A display driver circuit comprising:

• a source driver integrated circuit (IC) configured to transmit an analog voltage to a display panel;
• a gate driver integrated circuit (IC) configured to control a gate of the display panel so that the analog voltage is provided to a storage device associated with the display panel;
• a controller configured to control the source driver IC and the gate driver IC based on a signal received from a host;
• and
• a gamma adjustment circuit configured to transmit the analog voltage to the source driver IC, the gamma adjustment circuit including,
• an amplifier including a cascade differential amplifier and a common source (CS) amplifier, the cascade differential amplifier configured to receive a first signal, and to generate a second signal based on the first signal, the CS amplifier configured to receive the second signal, and to generate a third signal based on the second signal,
• a first decoder including a first output terminal and a second output terminal different from the first output terminal, the first decoder configured to receive the third signal from the CS amplifier, the first decoder configured to select, based on a first selection signal, one of the first output terminal and the second output terminal as a selected output terminal, to provide a fourth signal to the selected output terminal such that the first decoder outputs the fourth signal to the first output terminal in response to the first selection signal being a first value and outputs the fourth signal to the second output terminal in response to the first selection signal being a second value, the first decoder configured to provide the fourth signal to the source driver IC as the analog voltage and
• a second decoder including a first input terminal and a second input terminal connected to the first output terminal and the second output terminal of the first decoder, respectively.

A display driver circuit comprising:

• a source driver integrated circuit (IC) configured to transmit an analog voltage to a display panel;
• a gate driver integrated circuit (IC) configured to control a gate of the display panel so that the analog voltage is provided to a storage device associated with the display panel;
• a controller configured to control the source driver IC and the gate driver IC based on a signal received from a host;
• and
• a gamma adjustment circuit configured to transmit the analog voltage to the source driver IC, the gamma adjustment circuit including,
• a first decoder including an input terminal, a first output terminal and a second output terminal, the first decoder configured to connect the input terminal to one of the first output terminal and the second output terminal based on a value from a second register, the first output terminal connected to a first node and the second output terminal connected to a second node, the first node and the second node having a first resistor connected therebetween, the first decoder configured to provide the analog voltage to the source driver IC,
• a second decoder including a first input terminal, a second input terminal and an output terminal, the first input terminal and the second input terminal of the second decoder connected to the first output terminal and the second output terminal of the first decoder, respectively, and
• an amplifier including a negative input terminal, a positive input terminal and an output terminal, the negative input terminal of the amplifier being connected to the output terminal of the second decoder, and the output terminal of the amplifier being connected to the input terminal of the first decoder.