Voltage detection circuit, display driver, and display device

A voltage detection circuit, provided for comparing magnitudes of a reference voltage and each of first to nth voltages, n being an integer of 2 or more, and outputting first to nth voltage detection signals indicating whether the respective first to nth voltages are higher than the reference voltage,

• wherein the voltage detection circuit comprises:
• a self-bias unit, receiving the reference voltage, and generating a self-bias voltage based on the reference voltage;
• and
• first to nth detection units, individually receiving the first to nth voltages, and individually outputting the first to nth voltage detection signals,
• the self-bias unit comprises:
• a first transistor and a second transistor, having mutually different conductive types, wherein respective drains of the first and second transistors are connected with each other via a first node, and the first and second transistors generate, as the self-bias voltage, a voltage occurring at the first node by receiving the reference voltage at respective gates of the first and second transistors;
• a third transistor, receiving, at a gate of the third transistor, the self-bias voltage, and supplying a current corresponding to a difference between a voltage at a source of the third transistor and the self-bias voltage to a source of the first transistor;
• and
• a fourth transistor, receiving, at a gate of the fourth transistor, the self-bias voltage, and supplying a current corresponding to a difference between a voltage at a source of the fourth transistor and the self-bias voltage to a source of the second transistor,
• each of the first to nth detection unit comprises:
• a fifth transistor and a sixth transistor, having mutually different conductive types, wherein respective drains of the fifth and sixth transistors are connected, and, with respective gates of the fifth and sixth transistors receiving one of the first to nth voltages, the fifth and sixth transistors output a voltage generated at the respective drains as one of the first to nth voltage detection signals;
• a seventh transistor, receiving, at a gate of the seventh transistor, the self-bias voltage, and supplying a current corresponding to a difference between a voltage at a source of the seventh transistor and the self-bias voltage to a source of the fifth transistor;
• and
• an eighth transistor, receiving, at a gate of the eighth transistor, the self-bias voltage, and supplying a current corresponding to a difference between a voltage at a source of the eighth transistor and the self-bias voltage to a source of the sixth transistor, and
• the voltage detection circuit further comprises:
• at least one current source transistor, receiving a bias voltage at a gate of the current source transistor, and generating a drain current based on a difference between a voltage of a source of the current source transistor and the bias voltage as an operating current that flows through the first to fourth transistors of the self-bias unit and the fifth to eighth transistors of each of the first to nth detection units.