LIGHT EMITTING DIODE DRIVING CIRCUIT, AND DISPLAY DEVICE HAVING THE SAME
First Claim
1. A light-emitting-diode (LED) driving circuit, comprising:
- a current driving circuit configured to control current signals flowing through LED strings;
a level detector configured to detect a minimum detection voltage signal having a minimum voltage level among voltage signals of first terminals of the respective LED strings;
a comparing circuit configured to generate a first comparison output signal and a second comparison output signal based on a headroom-control reference voltage and the minimum detection voltage signal;
a digital control circuit configured to adjust a duty ratio of a gate control signal in a digital mode based on the first comparison output signal, the second comparison output signal and a control clock signal; and
a power supply circuit configured to generate an LED driving voltage in response to the gate control signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A light-emitting-diode (LED) driving circuit and a display device include a current driving circuit, a level detector, a comparing circuit, a digital control circuit, and a power supply circuit. The level detector detects a minimum detection voltage signal having a minimum voltage level among voltage signals of first terminals of respective LED strings. The comparing circuit generates a first comparison output signal and a second comparison output signal based on a headroom-control reference voltage and the minimum detection voltage signal. The digital control circuit adjusts a duty ratio of a gate control signal in a digital mode based on the first comparison output signal, the second comparison output signal and a control clock signal. Therefore, the LED driving circuit has a small area in a semiconductor integrated circuit.
-
Citations
20 Claims
-
1. A light-emitting-diode (LED) driving circuit, comprising:
-
a current driving circuit configured to control current signals flowing through LED strings; a level detector configured to detect a minimum detection voltage signal having a minimum voltage level among voltage signals of first terminals of the respective LED strings; a comparing circuit configured to generate a first comparison output signal and a second comparison output signal based on a headroom-control reference voltage and the minimum detection voltage signal; a digital control circuit configured to adjust a duty ratio of a gate control signal in a digital mode based on the first comparison output signal, the second comparison output signal and a control clock signal; and a power supply circuit configured to generate an LED driving voltage in response to the gate control signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A display device, comprising:
-
a display panel; a back-light driving circuit configured to detect a minimum detection voltage signal having a minimum voltage level among terminal voltage signals of respective light-emitting-diode (LED) strings, generate comparison output signals based on a headroom-control reference voltage and the minimum detection voltage signal, adjust a duty ratio of a gate control signal in a digital mode based on the comparison output signals and a control clock signal, and generate an LED driving voltage in response to the gate control signal; and a back-light unit including the LED strings, and configured to operate in response to the LED driving voltage and provide light to the display panel. - View Dependent Claims (13, 14, 15)
-
-
16. A light-emitting diode (LED) driving circuit including a power supply circuit to supply a driving voltage to an LED array, the driving circuit comprising:
-
a level detector to detect a minimum voltage output from the LED array; a comparing circuit to output a plurality of comparison signals based on the detected minimum voltage and a headroom-control reference voltage (VRHR); and a digital control circuit to output a gate control signal to a gate of a NMOS power transistor of the power circuit such that a duty ratio of the gate control signal is changed based on a detection voltage of the NMOS power transistor and the driving voltage of the LED array. - View Dependent Claims (17, 18, 19, 20)
-
Specification