Display driving circuit having short detection function
The present disclosure discloses a display driving circuit. The display driving circuit is configured to have a function of detecting a short of a data line occurring on a display panel.
1. A display driving circuit comprising:
a first output line connected to a first data line of a display panel;
a second output line connected to a second data line of the display panel;
a first detection line;
a first detection circuit including first and second transistors connected to a comparator and configured to output a first detection current to the first detection line,
wherein the first transistor provides a first copy current proportional to the first detection current to the comparator, and the second transistor provides a second copy current proportional to a first comparison current to the comparator, and
the comparator outputs a first detection signal corresponding to a difference between first detection current and the first comparison current by comparing the first detection current and the first comparison current;
a second detection line;
a second detection circuit configured to output a second detection current to the second detection line, and output a second detection signal corresponding to a change in the second detection current;
a first switching circuit configured to connect the first detection line to one of the first output line and the second output line; and
a second switching circuit configured to connect the second detection line to the other of the first output line and the second output line,
wherein, in the first switching state, the first switching circuit connects the first detection line to the first output line and the second switching circuit connects the second detection line to the second output line,
in the second switching state, the first switching circuit connects the first detection line to the second output line and the second switching circuit connects the second detection line to the first output line, and
the first switching state and the second switching state are alternately performed.
2. The display driving circuit according to claim 1 , wherein the first output line and the second output line are respectively configured between the first and second data lines which are adjacent to each other and first and second output buffers which output source signals of opposite polarities.
3. The display driving circuit according to claim 2 , further comprising:
a multiplexer configured to switch connections of the first output buffer and the second output buffer to the first output line and the second output line,
wherein the multiplexer sequentially performs a first selection mode of connecting the first output buffer to the first output line and connecting the second output buffer to the second output line and a second selection mode of connecting the first output buffer to the second output line and connecting the second output buffer to the first output line.
4. The display driving circuit according to claim 1 , wherein
the first switching circuit includes a first switch which switches between the first detection line and the first output line, and a second switch which switches between the first detection line and the second output line,
the second switching circuit includes a third switch which switches between the second detection line and the first output line, and a fourth switch which switches between the second detection line and the second output line, and
the first switch and the fourth switch are turned on in the first switching state, and the second switch and the third switch are turned on in the second switching state.
5. The display driving circuit according to claim 1 , wherein the first detection circuit comprises:
a first buffer configured to output the first detection current to the first detection line;
a first comparison voltage provider configured to provide a first comparison current of a preset level; and
a first comparison circuit configured to output the first detection signal by comparing the first detection current and the first comparison current,
wherein the first buffer receives a first test signal of, in a voltage range between a high voltage higher than a medium voltage and a low voltage lower than the medium voltage, a first voltage range between the high voltage and the medium voltage, and includes an output circuit which outputs the first detection current corresponding to the first test signal.
6. The display driving circuit according to claim 1 , wherein the first copy current obtained by copying the first detection current and the second copy current is obtained by copying the first comparison current.
7. The display driving circuit according to claim 1 , wherein the second detection circuit comprises:
a second buffer configured to output the second detection current to the second detection line;
a second comparison voltage provider configured to provide a second comparison current of a preset level; and
a second comparison circuit configured to output the second detection signal by comparing the second detection current and the second comparison current,
wherein the second buffer receives a second test signal of, in a voltage range between a high voltage higher than a medium voltage and a low voltage lower than the medium voltage, a second voltage range between the medium voltage and the low voltage, and includes an output circuit which outputs the second detection current corresponding to the second test signal.
8. The display driving circuit according to claim 7 , wherein the second comparison circuit outputs the second detection signal by comparing a third copy current obtained by copying the second detection current and a fourth copy current obtained by copying the second comparison current.
9. A display driving circuit comprising:
a first detection line;
a second detection line;
a first switching circuit configured to connect the first detection line to one output lines among odd-numbered first output lines which are connected to odd-numbered first data lines of a display panel and even-numbered second output lines which are connected to even-numbered second data lines of the display panel;
a second switching circuit configured to connect the second detection line to the other output lines among the first output lines and the second output lines;
a first detection circuit including first and second transistors connected to a comparator, and configured to output a first detection current to the first detection line, wherein
the first transistor provides a first copy current proportional to the first detection current to the comparator, and the second transistor provides a second copy current proportional to a first comparison current to the comparator, and
the comparator outputs a first detection signal corresponding to a difference between the first detection current and the first comparison current by comparing the first detection current and the first comparison current; and
a second detection circuit configured to output a second detection current to the second detection line, and output a second detection signal corresponding to a change in the second detection current,
wherein
the first switching state and the second switching state are alternately performed,
in the first switching state, the first switching circuit simultaneously connects the first detection line to the first output lines and the second switching circuit simultaneously connects the second detection line to the second output lines, and
in the second switching state, the first switching circuit simultaneously connects the first detection line to the second output lines and the second switching circuit simultaneously connects the second detection line to the first output lines.
10. The display driving circuit according to claim 9 , wherein
the first switching circuit and the second switching circuit alternately perform connections of a first switching state and a second switching state for a pair of a first output line and a second output line which are adjacent to each other,
the connections of the first switching state and the second switching state are performed in a time division manner by the unit of a pair of adjacent output lines,
in the first switching state, the first switching circuit connects the first detection line to the first output line and the second switching circuit connects the second detection line to the second output line, and
in the second switching state, the first switching circuit connects the first detection line to the second output line and the second switching circuit connects the second detection line to the first output line.
11. The display driving circuit according to claim 9 , wherein
the first output lines and the second output lines are classified into a first group and a second group,
a first switching state and a second switching state for the first group are alternately performed, and then, the first switching state and the second switching state for the second group are alternately performed,
in the first switching state, the first switching circuit simultaneously connects the first detection line to the first output lines and the second switching circuit simultaneously connects the second detection line to the second output lines, and
in the second switching state, the first switching circuit simultaneously connects the first detection line to the second output lines and the second switching circuit simultaneously connects the second detection line to the first output lines.
12. The display driving circuit according to claim 9 , wherein
the first output lines and the second output lines are classified into a first group and a second group,
the first detection circuit and the second detection circuit are configured for each of the first group and the second group,
a first switching state and a second switching state are alternately performed for each group,
in the first switching state, the first switching circuit simultaneously connects the first detection line to the first output lines and the second switching circuit simultaneously connects the second detection line to the second output lines, and
in the second switching state, the first switching circuit simultaneously connects the first detection line to the second output lines and the second switching circuit simultaneously connects the second detection line to the first output lines.
13. The display driving circuit according to claim 9 , wherein
the first output lines and the second output lines are classified into a first group and a second group,
the first detection circuit and the second detection circuit are configured for each of the first group and the second group,
in each group, the first switching circuit and the second switching circuit alternately perform connections of a first switching state and a second switching state for a pair of a first output line and a second output line which are adjacent to each other,
in each group, the connections of the first switching state and the second switching state are performed in a time division manner by the unit of a pair of adjacent output lines,
in the first switching state, the first switching circuit connects the first detection line to the first output lines and the second switching circuit connects the second detection line to the second output lines, and
in the second switching state, the first switching circuit connects the first detection line to the second output lines and the second switching circuit connects the second detection line to the first output lines.