Light emission control driver and display device including the same
A light emission control driver includes stages, each including: an input circuit controlling voltages of first and second nodes (N 1 , N 2 ) based on a first clock signal (CS) and one of a start signal and a carry signal; a first main circuit controlling a voltage of a third node (N 3 ) based on the voltage of N 1 and a second CS; a second main circuit controlling the voltage of N 3 based on the voltage of N 2 ; an output circuit controlling output of an emission control signal (ECS) based on the voltages of N 2 and N 3 ; a first auxiliary circuit controlling a low level output of the ECS from a first low level to a second low level based on the second CS; and a second auxiliary circuit controlling the low level output in a single step from a high level to the second low level based on the voltage of N 2.
1. A light emission control driver comprising:
stages configured to supply an emission control signal to emission control lines,
wherein each of the stages comprises:
an input circuit configured to control a voltage of a first node and a voltage of a second node based on a first clock signal and one of an emission start signal and a carry signal of a previous stage among the stages;
a first main circuit configured to control a voltage of a third node based on the voltage of the first node and a second clock signal;
a second main circuit configured to control the voltage of the third node based on the voltage of the second node such that the third node has a voltage level opposite a voltage level of the second node;
an output circuit configured to control the emission control signal output to an output terminal based on the voltage of the second node and the voltage of the third node;
a first auxiliary circuit configured to control a low level output of the emission control signal such that the emission control signal is further lowered from a first low level to a second low level based on the second clock signal; and
a second auxiliary circuit configured to control the low level output of the emission control signal in a single step from a high level to the second low level based on the voltage of the second node,
wherein the second auxiliary circuit comprises:
a fourth capacitor coupled between an eighth node and the output terminal;
a thirteenth transistor coupled between the second node and the eighth node, the thirteen transistor comprising a gate electrode coupled to a second power source; and
a fourteenth transistor coupled between the output terminal and the second power source, the fourteenth transistor comprising a gate electrode coupled to the eighth node.
2. The light emission control driver of claim 1 , wherein the fourth capacitor is configured to increase a magnitude of an absolute value of a voltage difference between the eighth node and the output terminal such that the emission control signal is changed to the second low level from the high level in response to a low level voltage being applied to the second node.
3. The light emission control driver of claim 1 , further comprising:
a twelfth transistor configured to limit a voltage drop width of the second node, the second node being coupled between the input circuit and the output circuit.
4. The light emission control driver of claim 3 , wherein:
the twelfth transistor is coupled between the second node and a fourth node; and
the twelfth transistor comprises a gate electrode coupled to the second power source.
5. The light emission control driver of claim 4 , wherein the first auxiliary circuit is configured to lower a voltage of the fourth node based on the voltage of the fourth node and the second clock signal.
6. The light emission control driver of claim 5 , wherein the first auxiliary circuit comprises:
a third capacitor coupled between the fourth node and a seventh node;
a third transistor coupled between the seventh node and a third input terminal configured to receive the second clock signal, the third transistor comprising a gate electrode coupled to the fourth node; and
a second transistor coupled between a first power source and the seventh node, the second transistor comprising a gate electrode coupled to the first node.
7. The light emission control driver of claim 6 , wherein the third capacitor is configured to further lower a low level of the voltage of the fourth node as the emission start signal or the carry signal of the previous stage changes to a low level.
8. The light emission control driver of claim 1 , wherein the input circuit comprises:
a first transistor coupled between a second node and a first input terminal configured to receive the one of the emission start signal and the carry signal, the first transistor comprising a gate electrode coupled to a second input terminal configured to receive the first clock signal;
a fourth transistor coupled between the first node and the second input terminal, the fourth transistor comprising a gate electrode coupled to the second node; and
a fifth transistor coupled between the first node and a second power source.
9. The light emission control driver of claim 1 , wherein the first main circuit comprises:
a sixth transistor coupled between the third node and a sixth node, the sixth transistor comprising a gate electrode coupled to a third input terminal configured to receive the second clock signal;
a seventh transistor coupled between the sixth node and the third input terminal, the seventh transistor comprising a gate electrode coupled to the first node; and
a second capacitor coupled between the sixth node and the first node.
10. The light emission control driver of claim 1 , wherein the second main circuit comprises:
an eighth transistor coupled between a first power source and the third node, the eighth transistor comprising a gate electrode coupled to the second node; and
a first capacitor coupled between the first power source and the third node.
11. The light emission control driver of claim 1 , wherein the output circuit comprises:
a ninth transistor coupled between a first power source and the output terminal, the ninth transistor comprising a gate electrode coupled to the third node; and
a tenth transistor coupled between the output terminal and a second power source, the tenth transistor comprising a gate electrode coupled to the second node.
12. The light emission control driver of claim 1 , further comprising:
an eleventh transistor configured to limit a voltage drop width of the first node, the first node being coupled between the input circuit and the first main circuit.
13. The light emission control driver of claim 12 , wherein the eleventh transistor comprises a gate electrode coupled to a second power source, the second power source being configured to maintain a turn-on state of the eleventh transistor.
14. A display device comprising:
pixels;
a scan driver configured to supply a scan signal to the pixels;
a data driver configured to supply a data signal to the pixels;
a light emission control driver comprising stages configured to supply an emission control signal to the pixels; and
a timing controller configured to control driving of the scan driver, the data driver, and the light emission control driver,
wherein each of the stages comprises:
an input circuit configured to control a voltage of a first node and a voltage of a second node based on a first clock signal and one of an emission start signal and a carry signal of a previous stage;
a first main circuit configured to control a voltage of a third node based on the voltage of the first node and a second clock signal;
a second main circuit configured to control the voltage of the third node based on the voltage of the second node such that the third node has a voltage level opposite a voltage level of the second node;
an output circuit configured to control an emission control signal output to an output terminal based on the voltage of the second node and the voltage of the third node;
a first auxiliary circuit configured to control a low level output of the emission control signal such that the emission control signal is further lowered from a first low level to a second low level based on the second clock signal; and
a second auxiliary circuit configured to control the low level output of the emission control signal in a single step from a high level to the second low level based on the voltage of the second node,
wherein the second auxiliary circuit comprises:
a fourth capacitor coupled between an eighth node and the output terminal;
a thirteenth transistor coupled between the second node and the eighth node, the thirteen transistor comprising a gate electrode coupled to a second power source; and
a fourteenth transistor coupled between the output terminal and the second power source, the fourteenth transistor comprising a gate electrode coupled to the eighth node.
15. The display device of claim 14 , wherein the fourth capacitor is configured to increase a magnitude of an absolute value of a voltage difference between the eighth node and the output terminal such that the emission control signal is changed to the second low level from the high level in response to a low level voltage being applied to the second node.
16. The display device of claim 14 , wherein the output circuit comprises:
a ninth transistor coupled between a first power source and the output terminal, the ninth transistor comprising a gate electrode coupled to the third node; and
a tenth transistor coupled between the output terminal and a second power source, the tenth transistor comprising a gate electrode coupled to the second node.
17. The display device of claim 14 , wherein:
periods of the first clock signal and the second clock signal are equivalent; and
the first clock signal and the second clock signal have a phase difference of a half period.
18. The display device of claim 14 , wherein the carry signal comprises an emission control signal of the previous stage.